How to learn physics effectively and efficiently How do you effectively study physics? How does one read a physics book instead or just staring at it for hours? 
(Apologies in advance if the question is ill-posed or too subjective in its current form to meet the requirements of the FAQ; I'd certainly appreciate any suggestions for its modification if need be.)
 A: If you are staring into textbooks for hours then you're doing it wrong. A good way is to workout the examples and the problems, first from the text, and then from other sources. Unless you apply what you read to some good problems, imagine what is written and make some of your own examples, you will only have an illusion of understanding. 
A: I would add that developing a physical intuition for the objects of study is an incredibly useful tool. This includes getting a sense for the scale of things, as well as consideration of fundamental things like energy transfer.  Also, understanding thoroughly simple models like simple harmonic oscillators or the concepts of symmetries can be a tremendous help, as these come up everywhere.  If you have access and have a specific subject question, the American Journal of Physics frequently has articles about educational avenues in physics that I've found useful in my studies.  Indeed, good luck! 
A: Read with a pad of paper beside you. When the author says 


*

*"It follows that ..."

*"Obviously ..."

*"From equations (1.137) and (5.17) we can see that ..."

*...

*...

*...


don't go on until you agree. Sometimes it really will be obvious; other times it may require many sheets of paper (Jackson was particularly bad for me).

This will require undisturbed time, and may be enhanced with some combination of enough sleep, sufficient nutrition, and a IV of the caffeinated beverage of your choice.
A: My key advice is don't rush.
While preparing for a Physics competition in high school, my mindset was to just rush and learn Physics as fast as possible. However, I've changed my mindset and realized that I need to master the material. It's more enjoyable gets you better grades and helps you when you apply your knowledge in future Physics courses. Of course there are ways to master the material faster and better using deliberate practice but don't rush!
The following is just a summary of Scott H Young's blog article:
Do lots of practice problems, make sure you understand parts that you don't understand, relate physics concepts with real life, never memorize what needs to be understood.
A: If you are really interested in physics, then you should always have a book about it within reach.  If you are not lucky enough to be a position to study full time, you have to find a way to study in the margins.  So, the first step is to start finding books, either hardcopy or electronic that you can read when you can spare a few moments.  It also helps to have a notebook and a pencil.  I have found it useful to actual copy the text of a section of a book or article verbatim by hand and work through problems as needed.  
It also helps to use online sources like youtube to watch good education videos.  The hardest part in all of this is probably trying to filter out bad physics from good physics.  It takes a long time to develop a sense of when things are good papers and when they are flatly wrong.  And, as always, spend some time to learn fourier transforms.
Addition:
One thing that I would work to understand is that while some people have natural talent when it comes to basic skills such as mathematics, in the end it is really a question of dedication and time (see the book Outliers which discusses the need to work at something for 10000 hours before you can master it).
A: I like the other answers, but here is some more advice:


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*Learning is an active process, in which you teach yourself. Nobody else can do that for you. So, when reading a textbook your job is to reconstruct it for yourself. Say it differently, make sense out of it in your own language. Ask yourself questions and try to answer them, and don't take anything on authority without making sure it sounds and feels right.  Only then you can be sure you really get it.

*Lots of practice - pianists spend hours stretching and flexing their fingers, doing scales, and all other sort of really boring and not at all glamorous activities. Physics is no different, lots of finger exercises are part of the game, even if they seem trivial.

*Also related to other answers - know yourself. Everyone is different, so part of the process is figuring out what works for you and what doesn't and make the necessary adjustments. Make sure you're having fun, at least most of the time, hard to sustain your interest otherwise.  
Good luck!
A: Here some suggestions pulling together various strings from this site and others and adding in my own thoughts. Check it though - some is way over my head:  


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*Be clear what your goal is 


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*an intuitive understanding of the functioning of the world around you (as well as further away) or 

*the ability to solve complex problems (or even breaking some new ground- that's something I won't even tackle here). Doing hardcore physics means you'll have to get deep into maths but this won't give you much for the intuitive understanding (or at least it's the much more laborious route).  


*Don't get too excited about trendy topics (string theory, quantum
mechanics and special relativity) before you have a decent grasp of
fundamentals in mechanics, waves and electromagnetism. Maybe you
really have found that the uncertainty principle does not hold but
everybody will think you are a clown if you don't know the basics of
kinematics (and a bit more than that). And "Let's talk about string
theory" is no longer that interesting as a pick-up line.

*Accept that you don't have to understand everything at once. If you
don't get it after you have spent some work on it - just memorise it
and get on. Sometimes (mainly for conceptual issues, like wave
particle duality) understanding basically means getting used to
something. Other times, you may just have a block and you'll get it
when you come back. But if you find yourself later knowing all the
math but understanding nothing about the physical meaning of it, you
should go back.

*If you are keen on the intuitive understanding, try to see the physics in whatever you are doing (why are you not falling through the chair). Do thought experiments, like whether a variable can rise to infinity (or fall to zero) and think what would happen. All this can be good fun with like-minded people - so get social on physics (I am afraid hardcore physics won't get you much social life, by contrast).

*Even if you are not in for hardcore phyiscs, get a modicum of maths.
You may find it tough talking about physics to physicists without
knowing the basics of calculus, for example.
If you are keen on hardcore physics and you don't have a strong
quantitative background, fixing your maths weakness is probably more
important than getting to know any physics. 

*And then solve problems. There are plenty of sources for problems. One (free) option is looking through past exam papers. 


*

*The UK exam boards for A-levels (approximately the same as advanced placement in the US) are publicly accessible and not bad - though not structured by topic. The AQA (one of the boards) papers are here.

*Ohio State University has compiled a fair number of practice problems for the Physics GRE.

*Even more advanced, Columbia University has a list of past exam papers that physics graduate students need to get through before they start their PhD research. 


*Boost your fluency with adaptive learning. Toktol physics (note - I am working for this site, still being expanded quite a bit) uses questions (up to lower university/Advanced Placement/A-level, covering pretty much the full curriculum) in a sequence adapted to one's ability, and spaced repetition to help people learn physics (and maths) as quickly as possible. Pearson and some other publishers also have online learning tools for physics but they tend to come with books or are only accessible for members of a class (e.g. Pearson's Mastering Physics).

*Get the right books: 


*

*The books tag on the (physics stackexchange) has many good lists of books for different purposes, and a community wiki post on books questions does a good job of pulling them altogether (including lists of free books).

*On the more hardcore side, physics books that are not targeted at physicists but at engineers or other disciplines where physics is an auxiliary subject can be quite good shortcuts (they are more focused on getting down to the matter). Another post mentions Physics for scientists and engineers by Randall D. Knight and I have nothing better to suggest. 

*On the simpler side, "Physics" by Tim Kirk and Neil Hodgson (for International Baccalaureate) is very thorough and also covers the trendier topics as optional sections. Conceptual Physics by Hewitt (targeted at US undergraduates, probably more at the less demanding side of the spectrum) is very soft on your maths muscles and pretty good at explaining. 


*Get the intuitive understanding by watching to some good video lectures.


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*Video lectures by Walter Levin (physics emeritus professor at MIT and a rock star of physics education) are extremely accessible (partly because of his stunt-like experimental setups) but very sound throughout. 

*The Physics for Future Presidents lectures (Berkeley) are also great for an even more casual introduction to physics. 

*There are more demanding (university-leve) physics lecture videos at Berkeley and MIT.

*Khan academy shows videos of Sal Khan, another educational rock star, explain physics (as well as maths and other stuff) by writing on a tablet. 


*Lecture ppts and lecture notes are informal and very focused on making the core points (that can be lost in massive books) and that's also what newcomers should focus on, so they are well worth looking for. Google, say, for ppt "escape velocity ppt" or "p-n junction pdf" will give you massive results. Flipping through those docs will get you some new visual ways of understanding concepts. 

*If you like playing with simulations, there are quite a few online free projects listed (but in a not too accessible way) by the US Department of Education. 
The University of Colorado has a good number of physics simulations, though again it is a bit tedious to go through them. Playing with such simulations will again building your  intuition. 
