The second in the Occlusion Block Tutorials by Jet Black Bebop for Far Cry 2.  Once more if you haven't seen the other 3 videos in the GenesisDevice.org Video Tutorial series for FC2 make sure you do.  You might even want to watch those first.  As these are from the days past of GD, the video quality is a little low, but the knowledge level is still very high - even by today's standards.

Second in the Far Cry 2 series is the Playable Zone Tutorial.  Jet does an excellent job of breaking it all down for you Far Cry 2 players.  Again this is old footage from the GenesisDevice.org days so forgive the poor quality.  The knowledge is still in HD though.