These revolvers come in a variety of barrel lengths and come with two cylinders, one is a .22 Magnum Rimfire, and one is a .22 LR rimfire.
The Single-Six is a cowboy-style revolver, with the cock-to-fire action. They come with adjustable sights, and Rugers are known for their quality. They also retain their value well, so if you want to sell or trade it later, you'll get good money for it.
A box of .22 LRs costs about 2 cents a round. You can use that for practice. It is not very powerful, about 80 foot-pounds of energy, so it is really not good for self-defense, but it is very good for practice. Cheap, with very light recoil.
The .22 Mag is at least twice as powerful as the .22 LR,but more expensive and if you use hollowpoints in the gun it would make for an adequate (if not spectacular) self-defense cartridge.
Then later on you can get a serious revolver, probably a .357 Magnum, and do most of your practicing your technique and aiming with the cheap .22LR ammo, then end your day at the range with a box or two of .38 Specials. Revolvers keep better for long periods of time being unused than semi-autos.
I would keep the revolver ready with some quality +P ammunition. The .38 Special +P adds a little bit of oomph to standard .38s without crossing into the flash-and-thunder level of a .357 Magnum. I read of a new .38 Special +P cartridge from Buffalo Bore that came highly praised in the magazine "Gun Tests", which does not take any advertising.
http://www.buffalobore.com/ammunition/default.htm#38splA Single-Six costs about $400, and a Ruger GP100 .357 Mag costs about $550. At least that's the MSRP. :-)
Another option for you is the pistol-caliber carbine. This is a short rifle that fires pistol ammunition. Ruger makes one chambered in 9mm and one in .40S&W. They are considered "long guns", and are easier to get than a pistol. Because the barrel is longer than a pistol's, you get more velocity and energy out of the ammunition, and it is easier to shoot than a pistol. Because you live in a limited-magazine-capacity state, you should go with the .40.