I have the two generations earlier T1i and like it well enough, and the t3i has a few things fixed on it over the T1i that it is a much better camera. if you can, play with the controls a bit, they aren't as intuitive as maybe the nikons, so if you can try a couple of brands its good.
the 18-55 is II is not bad for a stock lens people say. personally, when I bought mine, I used it two weekends and promptly bought a 15-85. SO much nicer, I absolutly love it outdoors as a walking around lens. However, its one big weakness is low light situations, its not horrible, but not great. the 18-55 is even worse. Like others said, for indoor work a 50mm/1.8 is going to be a really good, cheap pickup for that kind of thing. I picked one up recently, but haven't had much use for it so far, but its handy to have a around. The canons do have good lenses and the cameras can do a lot now to help you in the lower light situations. Another thing to look at would be getting a decent flash. I have so far just used the stock flash. Its not horrible, but if i was doing a lot of indoor use, i'd really want one.
Forum for Sniper 1's to MQ and anything autococking welcome.
Pics of some of My Collection
of 50+ rare and oddball cockers and other oddities