What website or source is the best way to find a summer internship or part time job?
This is a great question! Many schools pair with employers for a student job board/website. These list openings that companies have for both internship and full-time opportunities and are a great starting point for job hunting. Speaking with a career advisor at your school will help with this. I followed this path when I was in university to secure 3 summer internships.
Also, depending on the industry that you're interested in, you can Google companies that you admire or are leaders in that industry and check their careers pages to see if they have student positions.
Hope this helps!