Best Keyboard Shortcuts

Getting used to using your keyboard exclusively and leaving your mouse behind will make you much more efficient at performing any task on any Windows system. I use the following keyboard shortcuts every day:
Windows key + R = Run menu
This is usually followed by:
cmd = Command Prompt
iexplore + "web address" = Internet Explorer
compmgmt.msc = Computer Management
dhcpmgmt.msc = DHCP Management
dnsmgmt.msc = DNS Management
services.msc = Services
eventvwr = Event Viewer
dsa.msc = Active Directory Users and Computers
dssite.msc = Active Directory Sites and Services
Windows key + E = Explorer

ALT + Tab = Switch between windows
ALT, Space, X = Maximize window
CTRL + Shift + Esc = Task Manager
Windows key + Break = System properties
Windows key + F = Search
Windows key + D = Hide/Display all windows
CTRL + C = copy
CTRL + X = cut
CTRL + V = paste
Also don't forget about the "Right-click" key next to the right Windows key on your keyboard. Using the arrows and that key can get just about anything done once you've opened up any program. 

Windows Run Commands

Accessibility Controls - access.cpl
Accessibility Wizard - accwiz
Add Hardware Wizard - hdwwiz.cpl
Add/Remove Programs - appwiz.cpl
Administrative Tools - control admintools
Adobe Acrobat (if installed) - acrobat
Adobe Designer (if installed) - acrodist
Adobe Distiller (if installed) - acrodist
Adobe ImageReady (if installed) - imageready
Adobe Photoshop (if installed) - photoshop
Automatic Updates - wuaucpl.cpl
Bluetooth Transfer Wizard - fsquirt
Calculator - calc
Certificate Manager - certmgr.msc
Character Map - charmap
Check Disk Utility - chkdsk
Clipboard Viewer - clipbrd
Command Prompt - cmd
Component Services - dcomcnfg
Computer Management - compmgmt.msc
Control Panel - control
Date and Time Properties - timedate.cpl
DDE Shares - ddeshare
Device Manager - devmgmt.msc
Direct X Control Panel (If Installed)* - directx.cpl
Direct X Troubleshooter - dxdiag
Disk Cleanup Utility - cleanmgr
Disk Defragment - dfrg.msc
Disk Management - diskmgmt.msc
Disk Partition Manager - diskpart
Display Properties - control desktop
Display Properties - desk.cpl
Display Properties (w/Appearance Tab Preselected) - control color
Dr. Watson System Troubleshooting Utility - drwtsn32
Driver Verifier Utility - verifier