A recruiter will ask you why you want to join, and what job type you would like to pursue. The recruiter will try to fill positions that are hard to fill, but if you have a specific job type you want to pursue like IT, Medical, or Engineering be sure to tell them you want a guarantee "A" School prior to signing an enlistment contract, also ask about signing bonuses. If you have a degree be sure to let them know you may be eligible for special programs.

Really about gathering a portfolio to make yourself look more marketable. Resume, recommendation letters, transcripts, narrative, etc. Of course, tests such as the ASVAB play a major role in your placement. The higher the score, the more jobs that are available to you.