What do I say about salary history?

I have two questions about salary history. First, what should I put in a cover letter when the job ad says to include salary history? Second, what if an employer asks me in an interview about my salary history? I’ve only had unpaid internships and I feel dumb saying “I have no salary history.”

Job postings that do not include company names

Why is it that many jobs I see posted on online job sites don’t name the company. Is this a scam? I’m not sure if I should respond to ads like these.

Using a Professor as a Reference

I'm a recent graduate and I would like to use a professor as a reference. Is there a certain protocol I need to follow in order to ask permission for use of his/her name as a reference?

The value of an unpaid internship

Are unpaid internships legitimate? It seems to me these companies are just trying to get cheap labor from college students.

What does “Principals Only” mean in a job posting?

Sometimes I see ‘Principals Only” in online job postings. I don’t know if I can apply to these jobs or not. What’s this all about?

What's a Not For Profit?

I feel pretty dumb asking this, but what exactly is a “not for profit?” I keep hearing I should look for a job at a not for profit, but I don’t even know what it is. And are there paying jobs or is it all volunteering?

I need an internship!

Help! I’m graduating in May and I think I should really get an internship before I graduate. Is it too late for this semester? Or next Spring?