We ran into this problem since at the time we bought VGC direct, they were not licensed to sell in the state of Hawaii.
I went to make the purchase on a trip with our best friend (who had formerly been our roommate and probably will be again), and my nephew while DH had to stay at home and work. I tried to call ahead of time to set up paperwork but they really didn't want to do anything over the phone since I couldn't sign any papers.
So in order to have DH on the contract, our options were 1) Have it in my name and amend the contract to add DH at a later date, or 2) Put DH on the contract, list him as having an address in a state they could sell to and mail/fax all the paperwork back and forth (we were not financing so there wasn't a tremendous deal). Since our best friend lived in California we put his address down as DH's address and I think its still on there, with our Hawaii address on my part of the contract and now they send all mailings to both addresses. We just left it that way since we'll probably be moving in with this person in the next year or so and trust him, though nothing important went there after the initial sale anyways. So basically the contract was sent to the address in NorCal, then forwarded to us in Hawaii, then we mailed it back to
Disneyland DVC office. Kind of a hassle but it worked.
If there's anyone you could trust that lives in that state (or any state they are now licensed to sell in - eg. California, Hawaii, Florida, probably New York and Illinois), you might be able to use their address and take advantage of that route doing most of the transaction over the phone. It's expensive on shipping, etc though.
The signing will need to be notarized, and they have a notary on site. I'd recommend making up your mind on such things as home resort, use year, amount of points you need before you ever walk in the door by researching this site anyways. You might be able to ask them if you can sign and notarize a contract and leave it on file with them backdated or something like that if you aren't sure you want to pull the trigger while there. At the very least you have a 10 day rescind period if you do sign while there in which you can cancel the contract.