I posted a few rules to follow in my BDSM vs. Abuse article, but I never touched on the idea of dealing with a stalker.
Stalkers are notorious, because it's nearly impossible to do anything about them legally until it's too late. The best advice I can truly give about stalkers, and it's not good advice, is to:
First, take out a TRO (Temprary Restraining Order) against them at your local police station.
Second, let you local neighborhood watch know that you have a stalker and provide them with pictures of him/her and his or her vehicle, along with a written description and license plate number, if you have it.
Third, try to spend as much time as possible with other people. Friends, family, even casual acquaintances. Most stalkers, from what I have read, don't like to approach their victims when other people are around. They like to have the person all to themselves.
Fourth, take a self-defense class. Learn how to deal with people if they grab you, learn how to get away form someone that assaults or attacks you, and learn how to use common items like car keys to damage your attacker and to give yourself time enough to flee.
Finally, after you've informed the police about this person, taken out the TRO against them, and notified your neighborhood watch, if you EVER saw this person within the boudaries listed in the TRO, then shoot them. I'm not kidding. Shoot them deader than shit. If they are voilating your TRO, then they are already legally considered a threat in most areas, and shooting them is covered under the articles of self-defense in most states. It's similar to the law that says you can shoot people trespassing on your property. Those people are already considered to be threatening your life, so using lethal force against them is aceeptable.
Like I said, this might not be good advice, because it seems a bit drastic, but it's better to be safe and extra, extra careful than it is to wind up on the front page of the newspaper.