That is a step in the right direction and you're off to a good start. I'm going out on a limb here and assuming you actually read the FAQ's on the site and if you haven't I suggest you take a look over there right now
, any other questions can be directed to your AV rep in person (assuming they have time to chat) cause it's so much easier to get immediate answers in person.
The only real thing you can get outside of this site is gear and is available new or used online (ebay, craigslist, other OEM/specialty companies who manufacture, etc.) or you can take a look at your local army surplus store and try on the gear and ask questions before you buy. To get guns the only place really is here, any other place outside of this site either suck or are at least loosely affiliated with this site in some way (Mach1, 007, CAS, etc.). Also to answer your question, yes there are a lot of used guns in the Classifieds section some stock and used a few times, some upgraded to the tits and used heavily.
EDIT: There is also a section for retailers who support the site (read: sponsor and pay for the site costs so they can advertise) who sell NIB guns and you can sometimes custom order guns but it may cost significantly more than getting used or having a retailer bring common guns in.