You will often find that asking the person sitting next to you is the quickest way to an answer. However, the students around you need to work on their projects, too. Depending on what time you are in the lab, you may find consultants, who circulate around the terminal rooms (look for the "consultant on duty" signs they put up, usually on top of the monitor they're using or on the desk near them). They are teaching assistants who hold office hours and can answer UNIX related questions. Also, the CSL staff offers Unix orientations at the start of each semester.
There are several books on Unix are available at the local bookstores. The world wide web (especially Google) is also a great place to find answers, tutorials, references, and forums regarding Unix. The CSL maintains a web page, complete with documentation, at http://www.cs.wisc.edu/CSDocs.
Course-related questions are best handled by your TA or professor. This includes things like the locations of data files or specific libraries you need to link into your programs. The CSL staff are not programming consultants and should not be used as such.
There are some matters, however, that only the CSL staff can solve. These primarily pertain to administration and security, such as a nonexistent account or if you think that someone else knows your password. If you think there is a problem with the system software (as opposed to your own program), or a problem with the hardware (such as a hung workstation or broken keyboard), send mail to lab@cs.wisc.edu with an explanation of the problem. Be sure to fully describe the problem as best you can or your problem may not be understood. Mail to lab will be forwarded to the correct party to deal with your difficulty.