Check their website! Very often faculty will include instructions for how to join their lab on their website. Start there.
If there are not instructions on their website, or you cannot find their website, send them an email.
If you do not hear back within 1 week, email them again. Faculty often get 50-100+ emails a day. A gentle reminder is much appreciated.
The Introductory Email
Keep it short and to the point
Include the following information:
Your year at SJSU
Your career and research interests
Why you are interested in doing undergrad research at SJSU
Why you are interested in their lab
Use this worksheet to help you organize your emails
Example Email
Dear Dr. [Last Name],
I am a [#] year […] major. I am interested in getting involved in a research lab at SJSU because I would like to pursue a career in [field]. I am particularly interested in your [area of research] lab because I am fascinated by [topic]. Your research into [specific project] sounds really exciting. I have taken [relevant classes…] and I think your lab would be a good fit. Are you currently taking undergraduate research students? If so, I would like to learn more about the opportunities to join your lab.
Sincerely,
[your name and SID]