DEFINITELY get training. Try for the NRA Personal Protection In The Home class if there's one close enough to you- see http://www.nrahq.org/education/train...ictraining.asp
for a class locator tool and basic information on the class.
You should always identify a target before firing at it ( http://www.thefiringline.com/Misc/safetyrules.html
- Rule 4)- to do otherwise is courting tragedy. Getting your wife to handle the phone and call the cavalry is a good idea, taking cover in the bedroom/safe room and waiting is definitely adviseable, if you don't have children elsewhere in the home to secure.
You want the room you are in to stay dark, and to have lights on in other parts of the house- night lights, remote control lighting (X10 modules or the like will do fine), motion detector lights in the hallway outside the safe room, etc. Darkness is an advantage for you, light is a disadvantage to any intruder. You want to have a clear view of the entry door into the room you set up as a safe room from your cover, and you only want to have one entry door to have to cover- and a 'friendly wall' (no doors or windows) behind you if possible.
Keep in mind, the 911 tape is running. It will pick up most every sound in your safe room. One of the sounds it should pick up is your loud and clear verbal warning that the police are on the way, that you have a gun and will fire if necessary, that the intruder should leave immediately.
You need to have a home defense plan, to go along with other family emergency plans (for fires, weather emergencies, etc). Family emergency plans should each incorporate as many of the same elements as possible for simplicity's sake.
Your home should incorporate layers of defense- home defense should not start at your bedroom door. From the perimeter of your property on in, look at your home with the eyes of a criminal, find vulnerabilities, and harden them. There is a lot of material available on this subject- make use of it. It's a lot better for your home to fail a criminal's target selection process than for you to have to successfully defend it.