follow 'brk's advice on asking questions. just thought i'd mention. you should avoid asking about salary, benefits, etc. gives the image you care more about getting paid than the actual project. and besides, if you get an offer, those questions are easily answered in a page or two of an offer letter.
just ask about their project and business. but nothing you could have easily found out on your own.
Yeah, I forgot to mention,don't ask anything that is already answered on their page/blog.
Also don't ask about pay details until after they bring it up.
However, as far as options are concerned, you SHOULD (IMO) ask:
What is the size of the total pool?
What is the size of the employee pool?
How are the shares distributed in terms of preferred/common?
Under the current terms, what point do the preferred shares need to hit before the employee/common options participate?
Extreme and simple example: They could grant you 5 million common options out of a total pool of 100 million with an employee pool of 25 million. Which would sound like 5% of the company and a HUGE chunk of the employee pool. The investors and founders might have 50 million preferred shares between them, but if the terms say that the preferreds split the first $500M in an equity event before the common shares participate, your 5 million shares are never likely to see any value.
I wouldn't get too far down a rat-hole with this, but asking some good questions will usually help show that you're not option-drunk and easily bought off with big, but meaningless, numbers :)
just ask about their project and business. but nothing you could have easily found out on your own.