All you need to know is in the TiVo manual, mostly.
The only buttons that can be programmed to control your TV set or sound system is the Power/Volume/Mute/Input buttons. All other are only for TiVo control. Any further function you need to control your TV or sound system, you need its remote, or a universal.
You do have to press TiVo to get almost anywhere, but there are shortcuts:
From TiVo Central, you can press:
0 - Plays TiVo Animation (the one you get when you power on)
1 - Season Pass Manager
2 - To Do List
3 - Wishlists
4 - Search by Name
5 - Search by Channel
6 - Search by Time
7 - Manual Record
8 - TiVo Suggestions
9 - Showcases
There is a couple SPS codes, useful ones being 30 second skip (Go play a recording, and enter Select Play Select 3 0 Select; you will hear three dings, then you can press the ->| to skip ahead 30 seconds), and SPS9S which toggles a clock on the lower right corner.
Series 2 234 Hr Lifetime.
Window XP and Ubuntu Linux on my PCs.
Watching more and more in HD direct now.