The idea behind the Automatic timepiece is the fact that with daily wear you really never have to wind your timepiece.  Certain older Rolex's required a daily winding using the crown.  However, all Rolexes in the past 40 years or more are built with Auto-self winding mechanism which winds itself as you wear the timepiece.

This year Rolex has greatly enhanced the Power reserve on most of their timepieces by coming out with new calibers which nearly double the Power Reserve from 40 to  70 hours of reserve. When does this come in handy?  Say you take your watch off and leave it on your bed stand for 2 days.  Older Rolexes would require you to either wind them manually using the crown and to manually adjust the time to the current time.

The new Rolexes can go almost 3 days without winding them.  Not every Rolex has received the new caliber, but most have.  I would expect Rolex to address the other lines of Rolex timepieces and apply the new caliber's to them by next year.  Although Rolex hasn't caught up to the Panerai 10 Days of Power Reserve, the 70 hours of reserve does cut the difference and is more than sufficient for Rolex owners that use their timepiece on a daily basis.

If you do need to wind your Rolex it is recommended to do so before putting the timepiece on your wrist.  In order to manually wind your Rolex, you need to first unscrew the screw-down crown into the first popped out position.  Then wind the timepiece slowly in the clockwise position.  Be careful to not overwind the timepiece.  Remember that you will add charge to your timepiece as you wear it. Also, be careful to screw the crown down on the case so that you ensure waterproofness to your Rolex.

If you have multiple Rolexes or other timepieces and you would prefer them to always be wound and ready to go, then it is time to invest in a watch winder.  Winders will rotate the timepieces in either a clockwise position, counter clockwise, or both clockwise and counter clockwise.  For Rolex, the clockwise rotation is all that is needed.