gregmcc:I'm ready to have a go at this, What do I need to get started?
For an overview go to https://www.mythtv.org/detail/mythtv
For a real challenge you could go it alone from here https://www.mythtv.org/
I recommend that you check out the overview then join the NZ MythTV community http://lists.ourshack.com/mailman/listinfo/mythtvnz
and start asking questions. (Your questions will depend on your current understanding and skill level but you will find a welcoming community happy to help) I have found that everyone on the mailing list has been treated with respect, no matter what their skill level.
If you have the required hardware there will probably even be someone in your area happy to join you for a couple of hours with coffee and bikkies and you would then have a working system which can be expanded to use multiple Frontends.