Most students working in labs do so initially without pay.
First, look through your class schedule and decide how many hours per week you can work. The times that you have available will help determine which projects you can work on. These are all on campus, and easy to get to between classes. The bus leaves about once an hour, so this option is best for those who have several long blocks of time available, rather than just an hour or two between classes. Some professors in the clinical departments also have small labs.