First of all, don't get bogged down by trying to carve tableside. Though a common tradition in many families, it's perfectly fine to carve the turkey in the kitchen and bring the arranged platter to the table. This especially holds true if you're a novice at carving.
Use a carving knife or a chef's knife. The longer the knife, the better it will work, as a long, smooth slicing motion will make for better slices.
We used a long carving knife with oval indentations along the blade to reduce friction.
Be sure to let the turkey rest for at least 25 minutes before slicing: this helps the juices redistribute through the meat, making for a better-tasting turkey. (It also makes it easier to carve.)