joercny suggested this would be good for the newbie board...................it was written with NYC in mind, but 90% is useful to all....

Always take a 3 oz bottle of listerine with me. Fits nicely in the coat pocket. When I go to the pharmacy, I stock up on 4-6 of them and keep them handy. When the girl come in, ask her what she does. Ask her if she kisses. If she kisses, I ask her to have a gargle of listerine with me. When you're done, wrap your lips firmly around the neck of the bottle and tilt you head down, thus all the listerine flows back into the bottle w/o spilling. When you're done with your date, take another good gargle and rinse.
Also, absolutely take a small bottle of Purell hand sanitizer along and cover your scrotum, pubis, any other areas that got saliva on them as well as your hands. Oh, have the girl wipe her hands down thoroughly before you get it on. I have never had an objection to this and many of the girls have complimented me for being cleaner and more careful than their typical customer (what should we infer from that ?) and seem to be more relaxed on account of the extra care.
I learned the Purell trick from a guy who I would describe as a super-player. He swears he's never had herpes or anything else for taking the extra level of care.
The greatest risk will be to the girl who has peridontal diseases or oral lesions that might allow white blood cells in the customer's semen (oddly, its the white blood cells that have the HIV virus in them that are now believed to be the most infectious agent, not the "nude" HIV virus itself) to enter her bloodstream.
 BTW, if you are in this hobby at any level, do yourself the great favor of having a Hepatitis A and Hepatitis B series. Expensive but a real bargain compared to liver cancer or cihrossis. There's an excellent testing and vaccination clinic on  80 East 11 street, 2nd floor, I think, called Always Your Choice...212-677-1777.
 I see they have attractive young women in there who are obviously pros, so I think it is a well trusted place. They are non-judgemental and very understanding people.