Ebay Ebay Ebay, that's how I get and sell a lot of my stuff and I'm living on a very small budget. Also, talk to some local riders in your area and they might be able to hook you up with stuff.
Another thing, and I know this is gonna sound kinda silly, but if your birthday comes around or something like that and people ask what you want, go for gift certificates to the LBS that you like. It helped me get some new tires and shorts
The people here on this forum are very knowledgeable and can send you to sites that give good deals. Don't be afraid to ask and welcome to the riding world!