I know there is already a guide on this, but i want to share the way i convert movies for the EVO. I use Cyberlink Mediashow Espresso to convert my blu rays to work with the EVO. I like the High Def Quality and Cyberlink makes it fast and easy to do so. If anyone is intersted here are my settings for it. You can download a trial from Cyberlink if you want to try it. Also, Mediashow uses your computers GPU for encoding so it doesn't take as long for the conversion process.
Settings:
Profile: Custom Profile (create a new one)
Format: MPEG-4 (not avc one)
Resolution: 640x360 16x9
Bitrate: 720kbps
These settings are good because it keeps the file size to under 1gb. Even a longer movie will be under this as well, i know because i converted the blu ray of Avatar using these settings. Play back is awesome. You can do regular DVD's as well using this, though i personally only do blu ray for quality purposes.