Over on DtownTV they recently did a 3 part series on wireless flash using the Nikon SB-600, SB-800, and the new SB-900.
In Part one they cover how to set up a flash for wireless operation, tips from Joe, and how to trigger a wireless flash with your camera.
Part two goes over setting up channels on your SB800 and SB900 flashes, Joe’s SB900 tip is on using the flash zoom, and a demo on using flash groups with multiple flashes.
In the final episode (aka part 3) wraps up the series with SB800 and SB900 accessories, Joe’s tip on using IC Filters, and extending your flash use with battery packs.
You can download a very helpful .pdf from Nikon called "Fast Track to Wireless Speedlights".