Be familiar with your equipment. You're probably attending a workshop that will teach you techniques. If you don't know your camera, then you'll spend more time figuring out how to operate your camera than on photographic techniques. Well before you leave for your workshop, make sure you know all of your gear's functions. Don't just concentrate on the basics; make sure you know how to use key special functions, too.
Here's a good test: Get out your camera, grab a small flashlight, turn out all of the lights and work your way through setting up your camera for an exposure. This is what you might have to deal with during one of the workshop days if you're getting up before the sun and traveling to get that sunrise shot.
Rick Sammon (www.ricksammon.com) leads many of Outdoor Photographer's seminars (www.opseminar.com). He also mentioned being familiar with your camera. In addition, he suggested that in order to get the most out of any workshop, you should fully participate. Take every opportunity to get involved in the classes. And don't forget to share and mingle.
That last point is an excellent suggestion. A workshop is a great opportunity to share your experiences and to meet and learn from others. While it might be difficult for some to mingle, you're spending your hard-earned money and will get more out of the experience by sharing with others.
Rob Sheppard (www.robsheppardphoto.com) suggested thinking about what you want to get out of the workshop: "Participants should go to a workshop with both a set of questions they want answered and an open mind. You need to have some goals for the workshop reflected in questions, and be sure to ask them." He also mentioned that while you might have goals, you should also be prepared for the workshop to take you in directions you hadn't considered. If you just go with a list, expecting to check off items one by one, you'll probably be disappointed. An open mind can lead to new discoveries.
Rob suggests that students ask questions. I've yet to meet an instructor who was a good mind reader. If you sit back and hope your question might be answered, it probably won't be. Questions help the instructor understand what you're interested in. And don't let the fear of asking a "stupid" question slow you down.
Lastly, Rob thinks that a workshop should be an opportunity to try something new. This means you'll have to fight the urge to do the same thing in the same way that you've always done. Take advantage of the new environment that a workshop brings, as well as the sharing with the teacher and other students to expand your photographic thinking.
Good luck with the workshop. Oh, and my advice? Have fun!