I pretty much agree with the others. The most important thing, however, is to make sure you've googled their name and read through any online reviews. These days, almost everyone gets rated at places like yahoo, yelp, etc. and this is where you'll get your best info.
In fact, it can even help with the questions you ask. For example, if a lot of reviewers complain that the fettuccini was disgusting because it was cold, you could point this out and ask if they're aware of this complaint and what they've done to remedy it.
And if the reviews appear to come from credible reviewers and they're all good, you may not have to worry so much about a lot of questions, since they clearly know what they're doing.
