First thing I would also go through PinPics.com when you have time to see the pins you like. Build a wants list. Unless you are really going to get into pin trading, I would avoid the mad rush of Brave pins / PODMs pins. Remember, this is a hobby not an investment.
A very important point is never acquire a pin you dont like, meaning that you might be stuck with it.
All that being said, being near the park is a great start. The first thing I would do is go to the NFFC convention at the end of the month. You will find some great buys there; especially on older but nicer pins. You can get good deals as low as $3-$5 a pin which you can use to build your trader base. If you are building a trader base, i personally would go for pins you dont see everywhere. This is one the problems with the "hot" pins right now; if everyone buys it for a trader then everyone has it.
If you are going to buy pins on ebay, stay away from any auction that doesnt post the actual pins. Stay away from Hidden Mickeys. Stay away from any set that is under $2.50 per pin. I would buy sets of pins that has one or two pins that belong to your collection and the rest you can trade away.
Hope that helps.
kajtdd