models and try shooting a few of them. I would definitely try a Glock, a Springfield XD, and a Smith and Wesson M&P. I would recommend going with a standard caliber, too. I would steer you towards a 9mm for your first pistol. 9mm is relatively cheap, it's available everywhere, the combinations of loads and projectiles are staggering (from top of the line self-defense rounds to cheap surplus ball ammo), and the recoil is very manageable (something to consider if your wife is planning to use/shoot it).

I see a few people recommending shotguns and AR-15's for your first gun purchase...I would recommend against either of those for a novice. Shotguns have a heavy recoil and can be very punishing for an inexperienced shooter, and AR-15's are relatively complex to operate and maintain. I'd definitely steer you towards one of the standard 9mm handgun models with a simple trigger safety like a Glock. There is no easier gun in the world to operate...you simply insert the magazine, rack the slide, and you're ready to rock and roll.

I think you would be very well served by a Glock 17, or a Springfiled XD. Whatever you get, make sure you get some training, and buy a safe, too.

Edit: I think the advice given in an earlier post about getting a .22 pistol is sound. My first gun was a Ruger 10/22, and my second gun was a Ruger Mark I .22 pistol. I still have them both, and they are still among my favorite guns to shoot. There is no better caliber than .22 for mastering the fundamentals of shooting. While .22 isn't the ideal caliber for home or personal defense, it would still be better than a baseball bat or a golf club.