This is what my Girlfriend used to get the feel of firing a handgun.
http://www.pyramydair.com/p/walther-p22-blank-gun.shtml
Fires 9mm PAK blanks which sound like a .40 so when she fired the actual
Walther P22 (.22lr) it was alot easier for her. The Blank gun I linked made by Umarex is worth every penny, it even brakes down like the real one.
Now she loves going to the range, her favorite (mine too since the ammo is so wide spread and cheap) is the Savage Model 93R17 .17 HMR. My Dad liked ours so much he bought one for himself.
But yeah start off with a
rimfire if you just plan on going to a range because
centerfire ammo ain't cheap, if you can even find it. Look at all the
.223 to .22 conversion kits for the AR-15
for example. The real Walther P22 is easy to find, well made, and cheap to boot, also check out the
Taurus Tracker .17 HMR. It's a rimfire round like the 22LR but packs more punch and the ammo is much easier to find.
Rimfirecentral has alot of good info. Work your way up to the larger calibers. Nothing wrong with a nice stockpile.
For home defense nothing beats a properly loaded Mossberg 500.