For me, Windows Annoyances started it all.
The original book (for Win95 and NT4.0), which was spawned from this website was great. In addition to demystifying the registry explaining (among other tasty tidbits) how file associations really work under the hood, it also hooked me up with some excellent utilities including UltraEdit32 (which ruled as my favorite text editor for more than a decade - now its EditPad Pro). The Office '97, Win98 and XP versions of the book are/were also good, particularly: Windows XP Annoyances for Geeks. In addition to registry tweaks, these books reveal many other small but useful tips and tricks - e.g. One example: command line options for starting Explorer opened to a specific root folder ("%SystemRoot%\explorer.exe /n, /e, I:\HOME"). For the authoritative book (closest thing to a Windows Users Manual), however, I also always purchase the "Resource Kit" for each version of Windows (You know, the one that is about 4 inches thick).

I have not downgraded to Vista, so have not looked at that version of the Annoyances book.

I use TMPGenc 4.0 XPress. At $100, its not cheap, but it is a very high quality encoder that converts anything into anything else (including flash, divx, wmv, mpg1, mov, mpg2 and Dolby Digital AC3 audio used in DVDs). In addition to its high price, it is also quite intrusive/obtrusive/obnoxious in that it phones home (via internet connection) to verify the validity of the license almost every time you fire it up. However, as I said, it is an excellent and easy to use encoder and it produces very high quality output.