Email the professor:
- Say that you are interested in working in their lab for undergraduate research credits
- Ask if they might have room in their lab that semester
- Ask for an appointment to meet with them, and attach an unofficial copy of your college transcripts.
When you meet in person, you will want to ask things like:
- What sort of research would you have me working on?
- Will I have set hours?
- How will I be evaluated?
If you haven't met them before, try to get a sense of whether their personality will work well with yours. (You can also get some sense of this if you've had them as a professor and from talking to other students.)
If your working with them suits both you and the professor, have the professor sign a course permit. Decide with the professor whether to take one, two or three credits (depends on your needs and what projects the professor has for you).