Hi! I understand how you must feel, the game is pretty overwhelming to people who have never really been much into the franchise.
For info on how to get certain pokemon, I would suggest visiting Serebii.net
, they have everything and anything about the games and the franchise! If you click the link, it should lead you directly to the page on the Black and White games. On the right side, it will list EVERYTHING about the game and ANYTHING he wants to know about it!
If he's looking for pokemon, click the link that says 'Pokedex', or just click here to go straight to the pokedex. Here's a link to info on Rufflet!
As for trading, I think there's a section here for trainers to trade through Wifi, If you explained your situation, I'm sure they'd be more than happy to help you out! (and honest!)
Here's a link to the Wifi trading thread!
Gamestop is right, there are only special events that occur to get certain pokemon, although I think if you have AR you can easily get them through that. If you're looking for AR codes, I would suggest youtube, you can tell through the comments people give if the codes work or not, I always find that helpful.
I hope this helps! If you need anything else, don't be afraid to pm me! I have a lot of younger siblings and I know how it can be haha.