I mostly agree with everyone here on most things. First, .45 acp might be a tough round to learn on. 9mm is cheaper and lighter recoil, and starting on .22 is a good idea if you want to learn well, but requires you to buy two guns if you want home protection (trade-in is a good suggestion). Your best option for home protection in my opinion is the pump shot gun. However, don't expect bird shot to have a decisive effect, but basics was right on about not hurting any surroundings (including people your not shooting at), so what some experts suggest is to have the first one or two shells loaded with shot, 6 or smaller, and if you miss, have buckshot loaded behind that. Without a doubt buckshot is gunna be the best stopper. They say no. 1 has the best wounding ability. Check out this article.
http://www.firearmstactical.com/briefs10.htm
http://www.firearmstactical.com/briefs10.htm
