Just go. It's honestly not that scary. Everyone's lost in their own little world and no one even notices you. Prepare some generic questions to ask representatives and ask them if you can leave your resume.
I went to a small one. It's mad chaos, a ton of people.
It was really nervewracking, but it was easier than I expected to start talking to employers because they pretty much appraoch you. You just wander near their booth looking mildly intrigued, and they generally come over and go Hi, do you know about Company X?
xlb is right, everyone is in their own world. Be prepared to elbow some people. Basically I just put my resume in for everything I was mildly qualified for (not much). I got two job offers, so yes, it was successful. I wouldn't go to one again though, as most of the jobs there were things I was NOT interested in doing and SA causes me difficulty with, such as retail and cashiering and watching children.
I've been to a few. One was small and had only 15 companies. I've been to a couple of large ones with 100-150 companies. Large job fairs usually have websites which advertise the event and list the companies that will be attending. It's best to take a gander at the list and narrow down the companies that you may have some interest in because its easy to get lost and will inevitably spend more time just looking and thinking about whether or not to spend any time at the many stalls. I was nervous beforehand as any SA'er but I was under a lot of pressure to get a job and there really wasn't much of a choice. It was so much easier than I expected. The companies representatives see a lot of people throughout the day so they want to tell you their pitch in as fast and efficient as possible. They won't interview you. They might ask you what your interests and skills are and how you would benefit the company but that is the worst case scenario. Usually you would just ask about the positions available, the pay, the locations, the hours, how soon could you start if hired, and get them to give you their application and phone number to contact with. In other words, you are usually in control of the conversation in getting the information that is relevant to you. IT really is nothing to worry about and I'll bet you will be leaving feeling better about things.
I went to one and didn't really have a positive experience. I didn't even want to go in the first place because it's hard for me to win people over with my amazing conversation skills! But I had to do it just to get my parents off my back. But yeah, half the companies there seemed to only be concerned with getting their name out there by promoting their brand, not actual jobs.
The lady at the booth for a major newspaper was more concerned with trying to sign me up for a newspaper subscription than she was about discussing jobs there.
A well known Government agency was there. They wouldn't even take my resume. The only thing they'd tell me is "check the website" and hand me a pamphlet.
A staffing firm was there and they tested the crap out of me. Every 3rd question measured how outgoing or shy you were. I answered them honestly and sure enough I never heard from them after that.
In my opinion, having been to about a half dozen of them, they are a total waste of time. Its always the same companies at the fairs, and things I am not qualified to do or not good at. The jobs are either on the high or low end, but nothing that fits me. I went to one job fair and this dumbass recruiter didn't even know how to read my resume. Corporate America..what a joke!
It sounds like a mixed bag as far as those who like them and those who don't. What types of companies (off the top of your head) were there? Were they hiring for min. wage type jobs or careers requiring special skills? I have a college degree, but I'm sure I'd be looking outside my field. This recession sucks.
And what about attire? Were most of the people dressed up (shirt, tie, etc), or was it fairly casual?