You've made it to the end of your transaction.  Congratulations!  Whether you are the buyer or seller, there are a number of documents for you to approve at closing.  Closing does not happen the day you sign.  Closing happens after escrow has performed their agreed duties to all parties, the loan (if any) is funded and the deed is recorded. 

There are many legal documents.  It is your right to read them all.  Plan to spend three days in the escrow office if you do.  Most of the documents are legal boilerplate, putting into a standard contracts what you've already agreed to do.  Arguably, the most important documents are the settlement statements.  Escrow creates a settlement statement each for the buyer and seller.  They may be slightly different, since it is customary to keep the buyers loan costs private.  These settlement statements outline the costs associated with the transaction.  

The seller usually signs first.  The seller's closing costs are typically 1% of the sales price, depending on the cost of the home.  The buyer signs in a separate appointment.  The relevant paperwork for the buyer is the settlement statement and the loan documents.  The loan documents should match the estimated costs the lender is required to send the borrower a few days before closing.  A buyer's closing costs are also typically 1%, plus loan costs and prepaid interest. 

The important thing to remember is that signing documents should not be stressful.  If you are the seller, bring your estimated settlement sheet and make certain it matches you final estimate.  If you are the buyer, bring you're the estimated settlement sheets from both escrow and the lender and make certain they match the final documents.  There may be tiny changes, but they should be basically the same.  Whether you are the seller or the buyer, it is a good idea to know where your agent will be during your signing.  If you have questions the escrow closer cannot answer (rare) it's always good to be able to contact your agent.