I am wondering whether there's a good resource to find data about upcoming Lunar Eclipses.
For example, showing the percentage of the eclipse over time. Such as: 17:23 GMT - 0%, 17:40 GMT - 10%, etc.
Probably, a late answer. But, it is worth of answering this question. And, I can't resist myself...
I use the same Celestia here too. It's a completely offline free simulation software for real-time 3D space environment. In light of your question, Celestia has its own inbuilt Eclipse finder. You give a set of dates (possibly, a range), select the planet, select its moons and allow it to compute. Within barely 2 seconds, you get the approx. results. If you wanna look at it (in order to make sure whether I'm telling the truth), you could select
Have a look at this image, where I've used the range for upto 2 years from now...
How do I tell this? Well, I tested it for a solar eclipse. Once, I was lucky to see a ring-shaped solar eclipse around the start of 2010. But, I've already informed my friends some 2 months before the event, that we're gonna have this ring, directly above our head.
An excellent site for eclipse data, both lunar and solar, is NASA's Eclipse Web Site. It shows maps, tracks and illumination data for all upcoming eclipses. Find the date of the eclipse you're interested in and click on the link to find all the information you need.
For example, the total lunar eclipse on June 15, 2011 has this data:
Penumbral Eclipse Begins: 17:24:34 UT Partial Eclipse Begins: 18:22:56 UT Total Eclipse Begins: 19:22:30 UT Greatest Eclipse: 20:12:37 UT Total Eclipse Ends: 21:02:42 UT Partial Eclipse Ends: 22:02:15 UT Penumbral Eclipse Ends: 23:00:45 UT