When I first started hitting the weights, I went in and made a list of what equipment was even available at the gym I was using, so that I could get some idea what my options were. Even while I was doing this, one of the staff members came up and asked if I needed help with anything, so I got him to show me how to work two pieces of equipment, figuring I could build from there. There are a lot of places that will give you instructions and pictures along the way--including this site.
I had a good experience with an online personal trainer over at www.plusoneactive.com It was a lot less expensive than dealing with a personal trainer face to face at the gym, didn't require me to show up at specific times, and he ended up answering my questions and adjusting my routine within 24 hours of my providing feedback every time I did so. It is, admittedly, a bit more effort to deal with one online, though, as you have to be much more specific in wording your questions.
As for asking another gym member, that depends on your confidence. You could try asking a hot guy as a way to start up a conversation. But if you're really interested in getting your form right, you might instead want to ask a woman using the machine who looks like she knows what she's doing. My experience is that the women who actually use a weight machine more often do so with proper form than guys do (probably because some guys just want to see how large of weight they can lift, even if their form is terrible, they're likely to hurt themselves, aren't isolating the right muscles, etc.), and a lot of them seem to get a huge kick out of explaining to a *guy* how to do so. The added benefit of starting with a machine is that you get a sense of what an exercise should feel like, a spotter isn't generally necessary, and you can get an idea of what your weight range is before you move over to trying the same thing with free weights.