My advice is always the same in this area -- know yourself first and foremost, and recognize that jitters and a little anxiousness comes with the territory. The other person likely feels exactly the same way, so you probably both share that in common!

It sometimes helps to try and change the way you think of it and treat it more casually in your mind. The word "date" does have a lot of expectations and maybe pressure -- but it's pressure you're putting on yourself. Recognizing that and thinking of it more as just an opportunity to get to meet other interesting and entertaining folks (and if something happens, that's great, if not, oh well). I think that was the whole premise behind that dating service, "It's just lunch..." I think the person who started it recognized all this pressure some folks put on themselves and that was an attempt to just re-state the idea.

Remember, it's supposed to be fun!! So try and have some fun while doing it!

Good luck!