I also had a terrible fear of joining a gym. I thought that a 300+ woman could not possibly be comfortable in a "thin/male dominated atmosphere". I thought people would be looking at me all of the time, that they would be judging me or (ghast) come over and give me advice! I thought the people who worked at the gym would be constantly trying to sell me supplements or classes or training sessions, etc. etc. I thought I wouldn't understand any of the equipment and look like a fool in front of everyone. I was even afraid to call for a "look around" appointment, because I wasn't sure what to say to the person on the phone!
But, I decided I was going to do it anyway:
I called and said that I wasn't really sure what I was doing, but I thought I might be interested in joining a gym. The person on the phone was
very pleasant and actually sounded truly happy that I called (not "salesmen's happy"). He asked when I could come over, and even though it wasn't during his normal shift he agreed to meet me at my requested time the next day. (Yeah, I'm sure he got some incentive, but he was so pleasent I really felt he would have done so anyway.)
When we walked in (I took my SO along because I was too nervous to go alone), the first thing I noticed was that no one noticed me. No one looked, no one gawked. Even when I went to the desk, the person working there didn't say "why do
you want to join a gym" (as I half expected she would

), but let me know that I was expected. A guy came over, shook my hand, and led me around the gym-the cardio area, the machines and free weights, the women's locker room (well, I had to go in there alone), the pool, sauna, etc. During this entire time, I never once felt like he was pressuring me into joining, and when the tour was done, instead of hitting me with the "hard sale" I was expecting, he asked me if I wanted to know about their membership rates or think about it first.
Well, I chose to hear the rates, and yes, they weren't the cheapest thing I've ever signed up for but I did (and do) felt that the price is well worth it. I signed up (discount for 1 year membership, but month-by-month rates were also available. I wouldn't recommend a gym that locks you into long periods of time). My SO even signed up for a "part-time" membership where she gets to go anytime during the weekends and weekdays from open-4:00, and 7:30-close.
Then, came the first day actually "going" to the gym. I was nervous all over again. Was I supposed to just walk in? What did I do with this pass? What machines should I use? Swollowing, I entered and walked to the desk. The person took my pass and asked if I wanted a towel or lock. I said "yes" to both and went back to the locker. Fortunately, there was a little curtained booth for changing clothes- to this day I think I would have been in better physical shape if high-school gym class hadn't made us dress in front of each other. (Now I feel comfortable in shorts and just go dressed.)
I locked everything up, grabbed my towel (a bit scratchy, but not too bad) and headed out. Again, no one looked up to stare at the fat lady who was about to make a fool of herself... and, in fact, there were people of all shapes at the machines. I felt a lot of relief, and now it was time to pick a machine... Well, the only machine they had that I had ever used before was a treadmill, so I headed to the cardio area, climbed onto one (a much nicer one then they had at the university), and started playing with the buttons until I figured out what settings I wanted, and started.
For the first few weeks, I pretty much stuck with the treadmills and bikes. I am not the kind of person who feels comfortable asking others for help (even though I knew they had free training for anyone on the machines). However, I did get a chance to watch other people using the weight machines and decided that they seemed easy and safe enough. I started encorporating them into my workouts one at a time, and now spend more time using them then the cardio's. These days, I've started doing the same with the free weights, though I'm relying on training books to help ensure I don't hurt myself.
Finally, in all of the months that I've gone, not once has anyone tried to sell me anything, be it suppliment or class.
Well, I have to go back to work now (and no, I don't work at the gym!)...I've obviously gone on more than long enough. Let me finish by saying that I really do look forward to my time at the gym (well, most days

), and I do encourage you to at the very least go in for a tour. And, if you find yourself still interested, try out a few gyms before making a commitment. I know of some where I live that would NOT make me happy. Good luck!