SO, your interested in rc then? There are two big questions you need to ask, battery or nitro, on road or off.
We'll deal with the question of power first. The easiest way to answer this is how much time do you want to spend on this? If you want something that you can just take out of the box and it goes then you really, really should go for electric. If, on the other hand, you want to spend lots of time fiddling, you're quite into mechanical things and this is to be a full time hobby then nitro might be what you want.
Nitro is, on the whole, quicker than electric and, once you get the feel for that particular engine, it's not that hard to tune, to start with though it can be a $*%!£. One of the big things I keep hearing bandied about is that the sound adds a note of realism to it. To be honest it sound a bit like a race tuned scooter and if you or yor neighbours object to noise then DON'T get one, there loud! The final thing I have to say on these is you probably won't be able to use this in your garden as it will quickly eat up the space (and the grass) and there's no reverse gear.
Electric is great for the beginner and it's what I'd recommed anyone to start with. Firstly there still quick, cheaper, they can be tuned by simply replacing the motor and they go backwards! I have both electric and nitro and I still use them all the time as you can literally plug and play. Some peoople see elecric as beeing nitro's poorer relation but I read an article where someone converted there nitro buggy to electric and it accelerated far faster and had a slightly higher top speed!
Right, on of off road. For me it's simple, off road. On road cars are fun and on the whole a lot faster, but you have to go to a large car park and if you new to this you WILL crash and it WILL break, sorry very bias on this. I've seen it happen to many people and lightwieght plastic hitting a kerb at speed is messy. Off road however you can drive anywhere, they can do tricks and they're alot tougher. I've a truck (HPI Savage) I recently slammed into a fence a full speed and nothing happened! There not as fast but a whole lot more vesitile. If you choose off-road you'll now need to decide between monster truck, stadium truck and buggy.
I like buggys, simple as that. They handle far better, there quicker all round and there not american, what more do you want! Trucks are much better at tricks and on the whole will withstand knocks better and they work on long grass, unfortunatly there all tend to be top heavy. Take a buggy round a corner too fast and you'll power slide, do the same in a monster truck and it'll roll. Buggy do need much smother surfaces though as if they hit a pothole there more likley to flip. Stadium truck are essentially an in between step.
Right, that's the basics. I havn't tried to be even handed as I like nitro buggys so to say anything else would be dishonest. My favorite is actually the first rc car I bought and it's called the Condor Pro which I bought from the nice people at Nitrotek. If you want to start out in electric, why not get a Tamyia kit and build it yourself. It's really not that hard, they lay there kits out in an easy way and you'll know how to take it apart.
Final thing to say is if it all goes horribly horribly wrong then your local model shop will probably be a bit more helpful if you bought it from them than off the internet. I've had geat expiriences with on line shops but there's nothing like somone actually physically playing with the car.
this is very basic but I hope it helped.