A lot of gyms will lure you in with a few free sessions with one of their personal trainers when you sign up for a membership. I am a big fan of taking advantage of this offer, but don't let the gym pick your trainer. Instead, ask questions so you can learn a little bit about each of them and then pick the one that seems to suit you best. If you don't, chances are your gym will just assign a trainer who is available (i.e. has a wide open calendar) to you that you may or may not like, and you probably won't get the most out of your time with them. Better yet, if you can wait, check them out while you're at the gym before you make your choice. You may see a trainer whose style you really like, or dislike, which could help you pick.