sweet, tell me how the 18-55 IS performs. That seems like a pretty good way to start off, esp. the hood/ filter. I don't know much about filters (when I buy a new lens I know I'm getting one for it though), but make sure it's relatively high quality otherwise a good lens is wasted.
I have the Sandisk Ultra 2gb and I'm planning on buying a bigger size right now. Probably a Sandisk Extreme (prob.in 4gb or 8gb.. I think they come in 2,4,8,16 maybe more) because from what I've read they're more shockproof/waterproof and they're more secure. Plus I need another card for more space for a trip I'm taking next month and I think Sandisk is having a sale right now.
btw, on my XTi with the 2gb card empty I have [about] 2800 pics on the smallest res., 850 on the Medium I normally shoot, there's another diff. quality Medium which I have about 1500 on. If you're planning on shooting RAW then be warned because I only have a little more than 200 in RAW and a little over 100 in RAW + High Quality JPG.
I hope some of that helps you with your decisions etc.