I've had my Mac less than a week but I've learned soooooo much by browsing the boards, searching, and reading up. Stuff that, honestly, I wish there was just some big list of. So I figured I'd make my own. 
Feel free to jump in here with your own suggestions; I'll happily add them. If this gets some decent use a sticky might even be in order.
How To...
Link - Network w/ Windows computer to share files
Link - Uninstall an application
Link - Rip / Burn DVDs
Link - Word Processing options
Applications
Link - Master application DB (VersionTracker)
Link - Alternate web browsers (Firefox, Camino, et al)
Link - Span display across multiple monitors (Screen Spanning Doctor)
Link - Calibrate your monitor's output (SuperCal)
Link - iTunes controls in your menu bar (ByteController)
Link - Menu bar calendar (MenuCalendar)
Link - Automate system tasks (MacJanitor)
Link - Automate system tasks (Cocktail)
Link - Tweak hidden system settings (Tinker Tool)
Link - Mail display in Menu bar (Mail Ticker)
Link - Make Dock transparent / change background (Clear Dock)
Link - Super customize USB devices / buttons (USB Overdrive)
Feel free to jump in here with your own suggestions; I'll happily add them. If this gets some decent use a sticky might even be in order.
How To...
Link - Network w/ Windows computer to share files
Link - Uninstall an application
Link - Rip / Burn DVDs
Link - Word Processing options
Applications
Link - Master application DB (VersionTracker)
Link - Alternate web browsers (Firefox, Camino, et al)
Link - Span display across multiple monitors (Screen Spanning Doctor)
Link - Calibrate your monitor's output (SuperCal)
Link - iTunes controls in your menu bar (ByteController)
Link - Menu bar calendar (MenuCalendar)
Link - Automate system tasks (MacJanitor)
Link - Automate system tasks (Cocktail)
Link - Tweak hidden system settings (Tinker Tool)
Link - Mail display in Menu bar (Mail Ticker)
Link - Make Dock transparent / change background (Clear Dock)
Link - Super customize USB devices / buttons (USB Overdrive)