How was the universe created? I do not know much beyond high school Physics. Thus, I am asking this question from almost layman's perspective:

What, as per the best of our existing knowledge and widely accepted among the scientific community, are the models of creation of the universe, and what is their core argument?

 A: If you mean by world the earth, you can find a fairly good discussion at
http://en.wikipedia.org/wiki/Formation_and_evolution_of_the_Solar_System
If you mean by world the universe: 
The big bang is a singularity, and we can study scientifically only what came out of it. See, e.g.,
http://en.wikipedia.org/wiki/Big_Bang
Thus there is no model of creation of the universe widely accepted among the scientific community. 
However, there are various scientific speculations based on physical reasoning, e.g.,
Eternal inflation, http://arxiv.org/abs/hep-th/0702178
Extra dimensions, http://www.superstringtheory.com/cosmo/cosmo4.html
Big crunch, http://arxiv.org/pdf/hep-th/0108187
Cyclic universe, http://arxiv.org/abs/hep-th/0111098
Big bang particle lattice, http://www.awesomeanimator.com/bigbangstatevector.pdf
Now or in former times widely accepted models for the creation of the universe can be found not in science but in theology, e.g.,
http://www.catholic.com/tracts/creation-and-genesis
http://www.talkorigins.org
http://www.aljazeerah.info/Islamic%20Editorials/2007/October/Creation%20and%20Evolution%20in%20the%20Holy%20Qur%27an%20By%20Hassan%20El-Najjar.htm
http://www.answering-islam.org/Shamoun/creationdays.htm
or mythology, e.g.,
http://dept.cs.williams.edu/~lindsey/myths/myths.html
http://www.desy.de/gna/interpedia/greek_myth/creation.html
http://www.egyptartsite.com/crea.html
A: The most widely supported theory for the creation of the universe is the Big Bang Theory. It states that the universe was created about 13.7 billion years ago from a singularity (a very, very hot point with an infinitely small volume and infinitely large density) and it has been expanding ever since (so getting less dense and less hot). Click here for a timeline since the Big Bang. 
The 4 main arguments supporting this theory are sometimes called the 4 pillars of the Big Bang Theory, click here for an article regarding those core arguments. Also, this video regarding 'Olbers' Paradox' might be of interest to you too, it's actually one of the most blatantly obvious arguments for the Big Bang Theory.
Of course, there are alternate theories, but at the moment this is the most widely supported one.
A: The book about the first three minutes of the universe from Steven Weinberg mentioned in Jerry's comment, I've not yet read but it looks good from afar.
In his inflationary universe Alan Guth explains in a very accessible way the formarly unsolved problems in cosmology and how thinking about them lead him to the idea of inflation. The many personal notes and experiences Alan Guth has included in his book make it a lot of fun to read. 
The above two books due not directly explain the absolut beginning of the universe which would probably involve some kind of something-out-of-nothing process. To explain the very beginning of the universe some kind of quantum gravity is certainly needed, as for example explained by  Stephen Hawking here (this book is admittedly written in a very cheerful, and some would say over optimistic, tone) or by Martin Bojowald here (these are "lecture notes" but I could not find a popular book about this).
A: There are over 50 billion universes.  Our universe has over 50 billion galaxies.
  In our universe there are hundreds of millions intelligent civilizations.  Simply proven by math, and our unique knowledge of existence.
