This has to be the simplest, cheapest, and most effective way of getting video on your PocketPC that I have found. 2nd best would have to be Windows Media Encoder, but it has less predictable results and very few options (when it doesn't crash).
PocketDivXEncoder - Download and start converting your larger video files to a format reasonable for your pocket pc. Be sure to run on "2 Pass Encoding" for best results. I also found that the resulting size is slightly less then what it originally estimates. Just play around with it, very easy to use!
BetaPlayer - very straight forward video playing software for your PPC. I have found the latest "unstable" beta very stable, BTW.
-nic