I like davesgarden.com when I'm looking up how well a plant will do here. People will chime in to let you know how it works where they live (at the bottom of the specific plant page)

And these folks are cool: http://www.csrees.usda.gov/Extension/
(find your extension agent at that site)

I haven't bookmarked all my favorites on this computer, but I can get lost typing in "Plant name" and hitting Images...

(Rain is falling on my garden as we speak. I managed to snag two Climbing America roses for 1.00 each ( they were bare root and leafing out so they were marked way down) so after a long day I am very happy to not have to worry about watering them and the peas and the strawberries and the asparagus and the potatoes and the new hepatica, ginseng, and the old salvia and coreopsis and Indian pinks and lilies and ferns and wild azaleas and maypops and iris and ranunculus and blah blah blah that is growing everywhere...... I do love spring...)

And extracted the relevant links for my area. Thanks!

while looking for certain plants online. They have reivews of nurseries to order from online, a plant search feature that helps you find plants, forums, you name it. Last week I was going to order blueberry bushes from one place but discovered several negative reviews so decided to not get them from there thanks to Dave.

http://davesgarden.com/

but I do have one of their articles bookmarked on weeds:

Don't Kill Those Weeds!!!

I may go to one of the nicer local (and organic) nurseries today, but maybe I'll have a look around Dave's first, to see what they can tell me about growing in unusual containers (I have two halves of an old log on my patio to use...)