At the beginning of your upkeep, you may search your library for a basic land card, reveal that card, and put it into your hand. If you do, you skip your draw step this turn and shuffle your library.
10/4/2004 If you have more than one of these on the battlefield, you get to use them all and you don’t skip multiple draw steps.
10/4/2004 The “if you do” means “if you search your library”. You get to skip your draw step and shuffle your deck even if you don’t find (or choose not to find) a basic land.
10/4/2004 Because the “search” requires you to find a card with certain characteristics, you don’t have to find the card if you don’t want to.