Well...
I think others on here will ask you some basic questions first, like, what type of girl are you interested in seeing look-and age-wise? Personally, I like them all, but definitely the top girls out there that will provide a positive, affirming experience for a first-timer might be:
1. Kerry All-around number one in my book. Gorgeous, sexy, playful, funny the whole package...will take it as fast or as slow as you like.
2. Mandy If ya can't have number one go with her number two partner see above for her attributes
3. Zoe Never had the pleasure but certainly others have and I've yet to read or hear anything negative.
Regardless of the girl you choose if you are open and honest about this being your first-time, she will go at a pace and to a level that you will be comfortable with, thus ensuring your first time will be great and, the next time, even better.
Good hunting...