Here are a few suggestions on how to make yourself stand out (in a good way) at the job fair:
Look the part. Go with a full suit (I personally prefer a pantsuit so you don't have to worry about skirt length). If you're going into a conservative industry, go for a more traditional look: traditionally cut blouse of a more traditional color, sensible (polished) shoes, minimal accessories, professional hair, more buttons closed, neutral makeup, well-trimmed/manicured nails. If you're going into a more creative industry, you can get away with a more fashionably cut suit (just nothing skin tight and no cleavage), or a brighter color (maybe even a patterned) shirt, maybe 1-2 bold accessories to make a statement -- but remember less is more, and you should only do 1-2 of these things, max. It's better to err on the side of caution for your clothing choices; they'll remember you for your personality, but they often only remember the clothing if it sends the wrong message. Research the companies in advance. Instead of talking to every single company, pick the few that you really want to meet. See what openings/programs they have. Where do you think you'd fit? Why do you want to work there? How can you help them? What do you want to know about them? Find the easy answers for yourself, and hopefully your research will lead you to the "hard" questions that will show you really understand the challenges the company faces. This is what can really make you stand out. Get your resumé ready. If you're looking at several different types of jobs, try to tailor a resumé for each one. Focus on results, not just your duties. For example, maybe while working in a restaurant's kitchen, you developed a way of tracking the ingredients that resulted in 20% less waste of expired ingredients. Use percentages or straight $ amounts, whichever sounds more impressive. If you're not sure, make your best estimate -- but don't overstate anything, in case they contact your old employer and verify. Look for transferable skills. Waitressing requires you to work well with others, handle multiple tasks at the same time, and have great customer interaction skills. Line up a reference from your old job. (I presume your old boss may not be the best, but is there someone else on his/her level that you're 99.99% sure would give you a good recommendation? Or at least a coworker?) And do you have any other prior bosses to use as a reference? Prepare your elevator speech, along with answers to the most likely questions. Your elevator speech is your brief (20-30 second) self-introduction to the recruiter. It should make them think "Aha, this person sounds like a good match for position X," and then they'll ask you some questions, hopefully. There are lots of practice questions (you can find lists easily), but some really common ones are: describe a strength, describe a weakness (you want to describe something you honestly struggle with, but also how you cope with it and have worked to improve it -- e.g., I realized I wasn't very good about recognizing when I need assistance, but I've learned to set a reasonable time limit to try it on my own, and then ask for help if I've made no progress), describe a difficulty you've had with a coworker and how you overcame it (be very careful with this one... never speak negatively of an old job experience; always try to put a positive spin on it). What to bring: a padfolio containing paper, 10-20 copies of your resumé (be stingy with these; you don't want to run out, so only give them to companies you're genuinely interested in), business cards (for the companies not worth a resumé), 2-3 pens (make sure they work and don't smudge). Do not bring a bookbag. Keep your phone off and away. Before going, print out the map of the fair (if available). Circle the locations of your target companies, and plan the order of your visit. I recommend warming up on 2-3 other companies first (ones you might be interested in, but aren't at the top of your list). Then go to your targets. After you've talked to all your targets, then you can wander and see what else is available, but you want to make sure you hit your targets while you're fresh. Ask for business cards of everyone you talk to and want to follow up with (definitely everyone you give a resumé to!). As soon as you've stepped away from their booth (and I mean far enough away they can't see you), write on the back of the card a few facts you remember about them. Include personal as well as professional facts (dog - Millie - chews shoes). When you get home, start writing thank-you cards (or e-mails, if you don't have a street address), being as personal as you can (that's where those notes come in -- e.g., "I just saw that they have product X that is supposed to keep dogs from chewing shoes. I hope you're able to get Millie to leave your shoes alone!"). (Okay, the dog-chewing thing is a horrible example, actually, but you get the general idea...) Thank them for taking the time to talk with you, ask any follow up questions you've come up with, let them know you're applying for a position they mentioned, etc. A little known recruiting fact: timing is everything. If possible, get there when the fair first opens (but don't bug anyone who's still setting things up; come back later). If it's an all-day fair, avoid going right before lunch, or too close to the end of the day (when they just want to get home). Most importantly, relax and try to just be yourself. Let your personality shine through. People want to hire people they think they'd get along with, so the more relaxed, confident, and nice you are, the more they'll want to hire you.
Good luck at the career fair!