When going to a job fair, generally, you'll want to dress the same as you would for any important interview. That means a nice suit, or a jacket and skirt, and a few well chosen accessories. When in doubt, stick to conservative colors like black, gray, brown, and navy. If you wear jewelry, avoid anything too large or flashy. Because you may be on your feet for several hours, it's a good idea to find dress shoes that are also comfortable. Likewise, you'll want to make sure your outfit is comfortable for both sitting and walking. Find a nice case to carry your resume and materials; never take a backpack, or an oversized purse. Your overall appearance should be neat, clean, organized, and professional. Remember, you'll be talking with potential employers. Some of them may have to make a hiring decision based upon your brief meeting, so it's especially important to look your best.