Here’s some useful stuff that’s helped me in my staggering, stumbling trip through gardening. Maybe it’ll help you. (And then again, maybe it won’t. Honestly, there’s a lot that you only learn by shoving stuff in the ground and watching it die. Or not.)
PlantFiles – A brief dossier on just about anything you’re likely to find in a garden
NicheGardens.com – The best native plant nursery I’ve found. Plus, they do mail-order!
Ecosystem Gardening – A blog with a lot of good stuff about gardening for wildlife
USDA plants database – This won’t tell you how to grow it or even if it’s pretty…but it WILL tell you if it’s native, if it’s invasive, where it grows, if it’s endangered anywhere, and link you to a lot of other sites that have even more info. I usually find myself here at least once when considering a new plant.
Can’t recommend these two highly enough: