I'm a personal trainer, and I wouldn't consider myself useless.

Some gyms offer services for free when you're just getting started. The trainer would show you around and introduce you to some basic exercises.
It would probably serve you best to find a training program on Elite that you would like to try. Then, a personal trainer may be able to guide you in the "how to's" of exercise rather than the "what to do". I'm not sure if I would trust too many of them out there to write you an actual training cycle. I imagine that you'll get better results here.
Also, some do come at an extra cost that is quite expensive. I make pretty good money personal training. It really depends on your goals. And if you're lucky, it is possible to stumble upon a good personal trainer that knows his stuff. Get there experience, education, certifications, etc. Do they have experience with athletes, powerlifters, bodybuilders, etc.
You may also want to consider posting this in the Training Threads.