The best place to ask this is at
www.thehighroad.org they're an amazing source of wealth.
How experienced are you in terms of shooting? If you haven't taken a firearms safety course, I would sincerely recommend it before picking up your first pistol. I would also suggest you take the NRA's Self Defense course, which will teach you a great deal about how to defend yourself.
Are you defending your home, or your person? If this is for concealed carry, then make sure the weapon you buy is something you are always comfortable carrying.
If this is for purely home defense, consider a shotgun. There's a saying: "My handgun is designed to get me where my shotgun is."
edit: fixed your link