Heading out on post right now I have decided to take the advice of the spousal employment officer Brad (a great guy). He himself is a spouse and has been on post many times. In some cases he worked on other occasions he didn't. His advice to me, "prepare for everything, expect nothing". By this he means, take advantage of all the training, and opportunities available, but don't freak out if you get to post and you end up not working (particularly at first).
My added advice to you before you go on post is explore the wonderful world of hobbies. Long before you go on post take up a hobby that you can do yourself. Go to an art store, buy a camera, get a musical instrument, anything that you can find mentally gratifying. Do this before you get on post because it may take a few tries to find something you like and it would be horrible to find out on post that you just don't have the fingers to play the violin.