Sardyop,
Answer to the question about "how much info" depends solely on your risk preferences. I joined ASPD a few years ago because I did not want to take a risk of being busted by ellie or my SO. I also did not want to risk seeing a subpar provider. I wish we had access to all the discussions about screening info that we were willing to give vs. the ladies needed (Juan2fork and I had a lot of posts trying to help newbies on this issue)
The bottom line is, you can give all your personal information and make the reputable providers comfortable enough to see you anytime. That is one end of the spectrum but it always leaves you open to being discovered, busted or in some crazies' cases (please ladies, no offense is intended) even blackmail. Yes 99% of the providers have at least as much as you to lose but do you really want to take the risk of running into that 1% provider? I don't and never have.
If you don't mind spending a little bit more for your security, my suggestion is to do a public meet (coffee or a dinner date) where you pay for the providers time without any play time. If she gets comfortable with you, you'll meet for a rendez-vous and you have your first reference. You can either use that reference or the same way to see another provider and "BAM!" now you have two references that will hopefully allow you to seeany other provider.
That was the way I chose to start playing, and nobody has any information about me but my handle, my yahoo e-mail and my hobby phone. I can sleep at night knowing that there is no possibility of linking my handle to my name. Am I an extreme case? Maybe... But remember "just because you are paranoid, does not mean that they are not out to get you" Or in much nicer words, I'd rather be safe (very very safe) than be sorry.
HH