An interesting post at HR World talks about "30 Interview Questions You Can't Ask and 30 Sneaky, Legal Alternatives to Get the Same Info"
What I don't like about the post is the title. It presents the article in a light that the content doesn't follow, which brings us to what I do like about the post.
I like the fact that the authors encourage getting past the presumed cause questions (not allowed) and takes the interviewer to the real reasons one is asking the questions.
For instance, asking about religious persuasion is nosy and, clearly, not allowed. But if the purpose is to determine availability to work, say, Sunday mornings, then the author says to just ask if there would be any problems working the weekend hours.
As one commenter wrote:
The title made me think that it would be about how to ask slimy questions in a legal way, but I thought it was actually reasonable and helpful. I would much rather tell potential employers that I am available to work any day of the week than tell them that I am an atheist.
Anyway, I cannot attest to the accuracy of the advice (I'm far from an HR expert) but the article seems reasonable and informative about some of the legalities any employer probably needs to know.