An appointment is made to sign documents at the escrow office. Signing usually happens two to three days before the loan actually closes, but can happen on the day of closing. Closing is the recording of the new deed and the funding of the loan. The escrow officer will not make the appointment until they have received the loan documents. A cashier's check is required for the balance of the down payment. The escrow officer will call you with the correct amount. If funds are coming from another closing, those funds can be wired directly into your escrow account. The closing documents are recorded at the county and the lender "releases the funds". The next day the seller moves out. Then you get keys from me and can move in.
Make sure to tell all your friends to use Steve as their Realtor :)