Here's a great website I used when planning my wedding with lots of rose colors, pictures, etc.:
http://www.omniflora.com/e-prog.htm
One thing, however, is that the names on this site are sometimes different from the rose names that your florist will be familiar with. Sometimes those listed are "garden roses" and not available from hothouses for florists. So it's best to just describe the rose color you want to your florist, give color swatches, and then ask for samples of what will be used. I've heard of brides being very disappointed in the color if they didn't ask for a sample beforehand (and I had a nightmare florist at first who intended to use the smaller budded roses as opposed to the big ones - she never would clarify or give me a sample, so I kicked her to the curb!).
Just some thoughts for you!
Oh, and since we're on a message board, I used
www.weddingchannel.com for their boards when I was planning - it's an awesome community! Here's a
link to the main forum page, and a link to the
Cakes & Flowers threads. It's very similar to GreekChat in format, and you can get some wonderful ideas and resources. Good luck - and congratulations!