Hi Katie,
I used to do quite a bit of woodcarving and whittling before I injured my hands and took up scroll sawing.
Some whittlers use pocket knives, but in my experience the blades need to be fairly heavily modified, and they are not always comfortable in the hand. However for pocketknives look at "whittler" and "stockman" patterns.
Many whittlers use a strait bladed knife (sheepshank), though ones with a gently curved end (sloyd) are also popular. Both work well, though it's important to have a "pointy" end so you can work in tight spaces. An inch and a half to two inches long is usually a good length. Note that Scandinavian "pukko" knives are usually not pointy enough to work well for whittling, though they are good general purpose knives.
If you buy an expensive knife you are usually paying for an elaborate handle, which looks pretty but won't make the knife work any better. Simple handles and carbon steel blades are usually best.
Frost make a cheap good quality knife with a laminated blade for about $20, usually called a Swedish carving knife which is fairly easily obtainable. However the blade itself is very thick, and it can get tiring to push it through the wood.
Denny also make a range of excellent carving knives. They are cheap, well made, have blades made from O1 tool steel (as do all of the ones listed below)) and triple riveted oak handles. Denny's one and a half inch standard blade is probably the best choice.
http://wyn.org/dennyknife/a/knives/knives-straight/index.htmlPerhaps Drake Knives might be of interest also
http://www.drakeknives.com/Pinewood Forge makes excellent top quality Swedish style carving knives, which are designed for spoon carving.
http://www.pinewoodforge.com/If there is a carving group near where you friend lives, he/she would probably find it useful to join it. Advice on wood, how to shape you knife's handle and, and how to sharpen the blade are outside the scope of an email, but are still very important to know.
If all else fails ring up Smokey Mountain Woodcarvers and talk to them. They have a great range and give good advice.
http://www.woodcarvers.com/Hope this isn't too complicated, and helps.
Good luck,
Paul
