Hi Allen, and welcome to the Q&A Board,
I think the a510 would be fine for general close-up photos as you describe using macro mode (tripod recommended). Another camera that may interest you is the new Canon a610; it costs more and is slightly larger but has a twist and tilt LCD that is very useful for macro photography. I believe it also has a super macro mode.
If you decide to get the a510 you may find my blog helpful:
http://www.digicamhelp.com/canon-a510-blog/index.htm