There are a number of answers to you question Rodnogdog. Most all your flex-shaft tools handpieces take 1/8th and 1/4 inch shank burrs your better ones also take 3/32nd shank burrs. A good basic set of 1/8th inch shank carving diamond burrs is a good starter. you can get a set of 28 at woodcraft for about $27. If you are wanting to do rough shaping and smoothing out your deeper carving cuts then you will want bits for that. I use Saburr burrs I get from Woodcarver Supply. I find the flame shape and the ball are the most useful. They come in ex-coarse.coarse and fine. I prefer the fine for the way I use them. Like any thing else to do with carving the choices are many. And it depend on how you plan to use the tool and burrs. There is a learn curve with power carving. First is to let the tool and burr do the work. A light touch when starting is a must. I would recommend. testing it on scrap of the wood you are going to be working with. A burr can dig in quickly on softwood and bounce across the top on harder woods, leaving marks that are a pain to sand out. When it comes to the tool itself I would recommend a veritable speed. If you are just going to do light work, detail and cleanup. You may do fine with a Dermal type tool but if you are going to used for waist removal and on hardwoods. Then something like a Foredom. A flex-shaft that will do at leased 15000 rpm's . I use my tool for many different things from carving to jewelry, cleaning parts and buffing small objects, cutting and grinding. If you get in to high speed tools( rpm's over 30000) then the rules change on burrs. You need to make sure the ones you get are made for those speeds. It is a good idea to make use all your burrs are rated for the max rpm's on what ever tool you chose. I hope this is of some help. There are many types of burr, carbide double cut, ruby,ceramic, sapphire and the list goes on. I have wasted a fair amount of money just to learn that for carving I use the basic burrs I listed at the top was all I really needed .