I'll toss in my .02...


First, get training, and not from your brother. I'm not saying your brother isn't knowledgeable -- I have no way to know that -- but relatives are often not the best people to train us. Further, there is a lot that you can learn from a good training facility that you can't replicate on a normal firing range for safety reasons. Make sure that the FIRST training you get covers all of the legal issues pertinent to your state.

Second, the most important factor to me in choosing a handgun, especially for a new shooter, is fit. The better your chosen weapon fits your hand, the more naturally it will point* and the more accurate you will be with it. After you learn to properly grip a handgun, try a LOT of different guns with that proper grip. Try to rent a selection of those that feel best to you, and shoot them.

Third, well there is no third. But I'll toss an observation out here: There was study done on the un-nerving effect of racking a shotgun on criminals. Turns out, it doesn't really scare them. It does, however, give your position away. Just food for thought.

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*EDIT: That isn't to say pointing is the only benefit, though. A good fit also means you can manipulate the trigger properly, that the gun behaves better in recoil, that you can reach all the controls on it better, etc.