Here is the thread you want for blue diamond RC (on road)
Official 2011 Blue Diamond On Road Scene
If you are new to racing, just do sportsman. Sportsman at BD is usually gas and electric cars mixed together. It keeps all the new guys together so the 1/10th electric/gas classes arent crowded with first timers.
There arent any set "rules" to be honest. we are all honest and will run rubber tires and 10.5. A few people have come out with 8.5 or faster and we just dont take them seriously. Foams on electric cars are the other no-no.
If you dont have the right gear just come on out and see what other people are using and you might be able to pick up used gear for cheap! My first time on the track i came out with a TA05 with the hpi sidewinder brushless set-up with an NSX body. I didnt win, but it was awesome! your current car should do just fine. G-force hobbies is only 10-15 minutes away and stocks AE parts too.
If you have any other questions PM me and i'll gladly help you out!