Then you're probably OK with the usual Dremel stuff unless you want to invest in some real carbide burrs. Use double cut carbides for steel, and single cut (open fluted) for aluminum with wax to keep them from loading up. Follow up with stones for a nice, slightly rough finish on the intake ports. On the exhaust side, many tuners feel that polished is best to prevent carbon buildup. The other school of thought is that the slight layer of carbon helps to insulate against heat build up in the cylinder and send it to the expansion chamber where it does more good.
Take it easy, you can go too far and you can't put it back. You can always buy an extra cylinder to experiment with for more extreme porting mods.