Before signing that contract and spending money on a "Personal Trainer" make sure that the trainer is CERTIFIED - not just by the gym but by an organization such as ACE.
In addition, when you are in the gym by yourself, try to sneak a peek at the trainer during a session with another client. Is (s)he interested in what their client is doing? Are they being genuinely helpful?
99% of the "personal trainers" at the gym I belong to I would not pay 5 cents to 'train' me...most have been through the gym's 'certification program' which is NOT anywhere near the same as being ACE certified. Yet, they charge high prices as well...I'm usually at the gym earlier than the trainers but I have seen them looking very bored and not helpful in the least. They just follow a form workout for the most part...some of them chat with friends and/or other gym members during their time with the client.
Best bet is - if you feel you need a personal trainer, don't rely on your gym's trainer - go to http://www.acefitness.org/
and locate a CERTIFIED trainer who know's what (s)he's doing!