First of all, there is no right answer to this question; There are only opinions. Secondly, it sounds like you are on a budget not only with regard to this gun but also with regard to not being able to upgrade to a more powerful gun in a month. That being said:
I would not go with a .22. While they are nice, cheap and fun (I have a 10/22T rifle and 22S pistol), you will outgrow them very quickly.
Also, while revolvers have their purpose, I prefer to have the a semi-auto because they generally carry more rounds of ammo in a more compact package (and the good ones are as reliable as a revolver).
Finally, what to buy.
1. I would choose a gun from a major manufacturer (ie, Beretta, Glock, Sig, Ruger, S&W, HK, Walther, Colt, etc.) which has been proven over the years. The reason for this is that these guns are generally more reliable than newer models.
2. I would choose a gun with a 4-5 inch barrel. I presonally prefer the midsizes which are closer to 4.25 inches (ie, Glock 19.23, Walther P99, etc.) because they are good for home or carry.
3. I would choose a caliber of either 9mm, .40, or .45. These are the most popular, and thus plentiful and cheap to buy (especially the 9mm). Much of caliber choice depends on capacity, and thus most .45's hold less rounds than 9mm's of the same size. Keep in mind that with the new laws, magazines with more than 10 rounds are extremely expensive (75-125 bucks apeice). Thus, especially if you are not planning on shelling out the dough for hi-caps you may want to go with something with under or close to 10 rounds.
4. Finally, buy something you are comfortable with. If you can't rent and test fire the guns (which not all ranges do), pick them up and play with them (AFTER MAKING SURE THEY ARE EMPTY AND STILL NOT POINTING IT AT THE GUY BEHIND THE COUNTER). Make sure it feels comfortable. Make sure you can conceal it if you plan to carry it (and that they make holsters for that gun that you like). Make sure you can manipulate all the controls (ie, slide release, mag release, etc.). Make sure your hand fits around the grip. Make sure you like the way it looks (don't laugh, this is important to some people).
That's pretty much it. If you're like most of us, you will love your first gun but will want a second (and third and fourth) very quickly. Finally, you can't really go wrong with a Glock 19 or 23.