I am pretty new to Rc airplanes. I have been flying helis for about 2 years. Well I got a plane for free from a friend and started to play with it. I got it to work and have taught myself how to fly. It is much easier than I though. A lot easier than helis. I don't know why everyone says don't teach your self but that is a different topic. What I wanna know is when can I put floats on it. I want to fly in the river behind my house. Any suggestions?

If you fly in a River and the engine dies while taxying, and the current is much at all, you are screwed.

well goto
http://www.foamfloats.com/
there is all the info

What Wings said is correct. Make sure you have a way to chase it. I've heard some people use RC Boats to retrieve their planes. This, unfortunately, will only work if the plane is sitting in the water properly. Skis up - you're screwed!
Good luck!
KW_Counter

ps: I'm jealous, I live in the desert. No rivers, just year 'round flying.