PiazzaM - I guess I didn't answer all you're questions (& I was surprised to see it created a hyperlink when it posted).
We bought a resale package through The Timeshare Store. We checked it out on the Internet through the recommendation of friends and also many on these boards.
It seems to me they sell the full DVC package that people own. The packages range from very large all the way to 50 points. We e-mailed the company asking for information on a few. A rep contacted us via phone. We found one we were interested in, made an offer (price per point), the sellers countered & we came to an agreement on a selling price.
So far everything has been done via phone, fax or e-mail & overnight mail. We bought at OKW, which is not available to buy from Disney but is through resales.
Good luck w/ whatever you do. ----------