The subject really says it all – Phoronuix have made a thorough guide for us.
Find it here
For those that have never tried out MythTV before, it is much more than just a PVR (Personal Video Recorder) for Linux. MythTV is licensed under the GPL and is popular on such distributions as Knoppix (KnoppMyth), Fedora (MythDora), and Ubuntu, but can run on most any Linux distribution. MythTV is broken into a backend server and front-end client with the backend doing all of the recording while the MythTV front-end is just used for watching the recordings and interfacing with the backend. Some of the MythTV features include commercial skipping capabilities, smart schedule recordings, free TV listing data, and the standard PVR features you would expect like pausing, skipping, and rewinding live TV. MythTV also has a plug-in system, which allows the installation of extra MythTV front-end components like a web browser, games, and mail client. MythTV was started in 2002 by Isaac Richards with the most recent release of MythTV (v0.20) coming out on September 11, 2006.