Fridrich (CFOP) Method
Introduction
PLL is the final step of the Fridrich method. Unlike in the previous steps, it is not necessary to go slowly because there is nothing to look ahead for, so the algorithms can be done at full speed.
Setting Up
The most confusing part with PLL might me the setup and recognition. The easiest way to do this is with AUF, or "Adjusting Uface." This basically means that you have to turn the Ulayer a few times before getting one of the 21 possible cases. You have look for "blocks" of correctly connected lastlayer cubies. Two adjacent cubies are "connected" if their adjacent stickers are the same, so in the solved state, those two pieces would still remain next to each other. When you locate a block, turn the Ulayer so that the pieces in the block are in their proper locations. Then look at the other pieces to see which PLL case you have. Larger blocks have higher priority over smaller ones, so if you see a 3piece block and a 2piece block at the same time, you should put the 3piece block in the proper place.
The Cases
Case 1Edges Only 

Case 2Corners Only 

Case 32 Adjacent Corners + 2 Edges 

Case 42 Diagonal Corners + 2 Edges 

Case 53 Corner + 3 Edge Cycle 