Most guilds, that I am aware of, would be more interested in your class rather than a secondary profession. The class is like hunter, rogue, priest, warrior, etc. The professions include things like tailor, leatherworker, blacksmith, etc. You can only have 2 primary professions, but you can take up all the secondary professions in addition to your 2 primary professions. The secondary professions are fishing, cooking, and first aid. I recommend doing all the secondary professions, but that is just me. The
wow official web site gives a pretty good summary of all the professions.