Alexey Komissarouk has an excellent guide to tech internships. Whether you’re interested in a startup or an established tech company, you’ll find relavant information. Even if you are not interested in an internship, if you know someone who should be, forward them this link.
He breaks it down in to several areas:
1. How do I get a good internship.
2. How do I pick where to apply/work.
3. What you learn.
He writes this guide from experience, having interned for Facebook and 2bkco. Much of his advice boils down to talk to your contacts. Admittedly, for a group of folks as generally introverted as engineers (his target audience), this is challenging. However, it’s a skill that can be developed as well as any other.