Gun ammo education?

Per California law I am a few days out from bringing home my new Springfield XD .40. This is the first handgun that I have owned, so I am still learning. I do not seem to be able to find much information on ammunition. I am trying to learn about the different types of ammo that are available. I want to learn about velocity, grain, etc. Does any one have a good web sites they can recommend to me? From what I understand the type of ammo that you use is VERY important for home defense, at least for the legality of it if I have to use it. Glazier safety slugs have been recommended to me, but then again so have Federal safety slugs. The main purpose for this fire arm is home defense with some recreational shooting on the side. I have no idea!!! Please help!!!