The back of your owners manual should have many indicators for you to see what they are. For the odd ones that pop up on occasion you have crackberry. I dont personally know of a site with an icon legend, hope someone can provide that info for you.
I know that for sprint, you can go to the sprint website and search for the curve, and at the bottom you can click on a link for a pdf for the user manual. I'm on wap, so I can't see your carrier. But, just go to your carriers site to see what you can find.
Posted from my CrackBerry at wapforums.crackberry.com