My battery life is fantastic. Admittedly, I carry around an extra battery, just in case, but I've never used one full battery in a single day. Some people might, but with my experience, I'd doubt it for most.
Unfortunately, I don't have the funds for a lot of lenses, so I only have the kit lens (18-55mm) and the cheapest of the Canon lenses, the 50mm f/1.8 Mark II. In retrospect, I would recommend not getting the kit lens and just using the money for a better one. The 50mm is actually quite good, even though it's really just a cheap bit of plastic; if you have the money for it, go for the 50mm f/1.4 or the new 50mm f/1.2 instead. Those are much better in terms of quality and durability, and all three are incredible for portraiture. I'm looking into Sigma and Tamron zooms at the moment. If you want general advice, look for lenses with large apertures (small f/stops). They're fast and work in low light wonderfully.
I'll stop there for now. If you have specific questions, please feel free to ask! I should just write a book.