R/C Helicopter Pilots- I have Some Questions

I want to get into R/C helis but I have some questions. First of all, do I need a special radio? I have a Futaba Skysport 4 already. What I mean is, do I need a radio that has both a throttle and collective functions or are there 4 channel ones available. Secondly comes in learning to fly. Real Flight R/C sim is way too expensive and my club doesn't have a training program for helicopters. I have my "Wings" for fixed wing aircraft, I can fly near perfectly and do some simple tricks. Is it something you have to learn on your own, are there instructional videos, or should I find someone who already knows how that can teach me?
Lastly, give me some recomendations on good trainers. It must be easy to fly but easy on my wallet too.
Lastly, give me some recomendations on good trainers. It must be easy to fly but easy on my wallet too.