Finding Crappie is often the hardest part of Crappie fishing.  First you need to find what portion of the lake they are inhabiting and feeding from.  Generally

Crappie can be found in shallow water during the spring months when they spawn.  
Water four to eight foot deep is the place to fish during these months.  As the water warms they will first move into intermediate water that is ten to fifteen foot deep.  Later as mid summers rolls around they will be found in water as deep as twenty to thirty feet.
 
The one constant to always remember when trying to locate Crappie is to fish near wood.  Standing trees in the water and fallen timber are excellent places to locate Crappie.  There is a river near my house that I have fished for years for Smallmouth Bass.  Once I waded in the river a long way to a spot I had never fished before.  I saw several standing trees in the water and decided to fish this area.  I proceeded to catch twenty nice slab Crappie. After fishing this river for years and never catching one Crappie I caught twenty because I stumbled onto the right spot to fish for them.
 
My final piece of information on Crappie fishing is to pay attention to the water depth your bait is fished at.  Crappie are particular feeders, especially in summer.  While they may be suspended in water that is twenty five feet deep they will likely feed at one specific depth.  Before you consider an area dead be sure to fish in at several different depths to ensure a thorough coverage of the area.

To get the full "Learning To Crappie Fish - From The Beginning" article you'll need to download it here.