Re: What do you need to start?
Do you tie flies? If so, you already most of the tools needed: good scissors, bobins, bodkins...
If you use a pre-formed or completed grip then the only special tool you would need is a rod turner to keep the epoxy level as it cures, or you can do it by hand like Rip suggested. You'll just have to baby-sit the rod for a couple-few hours rather than walk away and let it turn. They are about $50-75.
You need a rat tail file or two to ream the grip to fit, a flat file to prep guide feet.
Check out some websites: Mudhole or Angler's Workshop both sell building tools and you can price out rod turners. There are plenty of other sites, those two have lots of stuff.