The kit lens will take ok macro shots, and is not bad with a close-up filter on it. I bought the 28-105 USM II and love it for a general all purpose lens. This lens is tough to take frog pics with without the close-up set though, as it can not focus as close.
I will note that if you have not had a DSLR before think long and hard about getting one. Not to say not to get one, just that they get expensive, with more lenses, flashes, lenses, etc etc... Did I say lenses..

I have not bought the 100mm macro yet, but plan to very soon. All of my recent ones are taken with the 28-105 USM II and a +4 close-up. To be honest my old Sony was easier to get a good shot of the frogs with, but I think the results out of this are getting better, and the DSLR clarity is unbeatable. It all depends on what you want. Do you want to spend a ton of money and carry a lot, or just take pics. I would recomend the Sony F717 which can be found now for about $500 if you don't want to drop a lot of cash. Just a thought, and check out
http://www.dpreview.com for some great reviews of cameras.
Uncle Sal said:
kyle, I may go for the canon myself, Can I get decent results with 18-55mm lens it comes with? (I mean taking nice close-up frog shots) Are you using the EF macro lense, I think 100?
Sal