J.S.:That depends on a few things. If it briar, which I assume it is it may come with a carbon layer already inside. If so then it will be black all the way down the inside of the bowl. If that is the case, no need to do anything but smoke a bowl. If you have bare wood inside then you need to start with about a half a bowl and smoke it. Do this a few times (10-12) until the heel and the bottom half of the bowl have a nice thin layer of cake starting to build. Then just smoke as normal.
If you have a pipe that does not have the pre-carbon layer and is not just wood inside (i.e., Peterson's are stained) I like to take a Q-tip with high proof alcohol (I like Everclear for this) and wipe the inside of the bowl down. The stain is alcohol based and after 4 or 5 times of doing this the alcohol will remove it completely. The stain actually seals the wood making it very hard to get a layer of cake started by removing it the cake will build up normally. Then I start out with the half of a bowl method described above.
Also, while you are breaking in a new pipe I try to smoke even slower than normal until a nice layer of cake builds up. No need to risk burning through a new pipe right from the start.