It's not really "signing up" - you are purchasing a real estate interest in a timeshare property. Once you purchase and close on a contract, you are an owner and can make reservations at the DVC resorts (or a few other locations - that's advanced DVC) using the points you purchased.
How do I sign up?
A) Do you mean for DVC? Are you buying direct or resale? Where are you buying from home, DCL, at WDW?
Whats the first thing am I supposed to do during signing?
A) Where are you buying from home, DCL, at WDW? This will make a difference in the way this question is answered.
What happens after I sign up?
A) If you mean DVC, start making reservation/planning for your next vacation.
The more details of your thoughts/ideas you can supply us, the better we can answer your questions. Also, how much research have you done about DVC on your own and on these boards?
Jedi, read all the stickies at the top of the DVC boards. Then stay on the DVC forums for the next 6 months reading every day so you know what you are buying. I am still learning something new everyday and spend a lot of time here on a daily basis. I purchased DVC last year after a couple months of exhaustive reading exclusively here on the Dis and DVCNews.com. The worst thing you could do is buy an expensive timeshare then not know a darn thing about it. Know the cancellation rules, UY, home resort, transfering, renting, borrowing, banking, Rule of Four, etc.
I agree with all these posts... do some research & understand how DVC works and how itcan work for you.
I know a couple that own a traditional Timeshare that they haven't been able to use in the past two years, for various reasons. unfortunately, they are still making payments on it. When I explained how DVC works... they wished they had bought in it instead, because of flexibility, etc.
Good luck!