Going to your first conference? Check out K. G. Schneider (Free Range Librarian Blog) advice: http://freerangelibrarian.com/2010/06/19/ala-conference-survival-tips-35-conferences-later/
Most conferences also offer to pair you with a mentor. Go to your association site or conference site to see if you can find a friend to help guide you.
Don’t forget to wear comfy shoes!