Here you will find a large collection of my oft used Windows keyboard shortcuts. Some are specifically for Windows 7, while others are more universally useful. Apologies in advance if you know most of these.

NB. Win is the WindowsKey

Using Windows itself, and Applications within it

Alt+Tab Tab through open windows
Alt+Shift+Tab Tab through open windows in reverse order
Alt+D Focus Address Bar
Alt+Enter Show Properties of the file/folder selected
Alt+Prt Scr Put a screenshot of the currently selected window into clipboard (explained)
Shift+Del Delete forever, bypassing Recycle Bin
Alt+F4 Close Application
Ctrl+F4 Close Tab
Ctrl+Shift+Enter Launch as elevated user (explained)
Ctrl+Shift+Esc Show Taskmanager
Win+D Show Desktop
Win+L Lock Workstation
Win+E Open Explorer
Win+R Open Run Dialog
Win+F Search
Win+P Cycle through display mode/output devices (explained)
Win+Down Minimise
Win+Up Maximise
Win+1/2/3 etc Switch between pinned apps according to number
Win+type search term Search index for item (explained)
F2 Rename
F5 Refresh

Navigating around text in documents, address bars etc

Ctrl+A Select All
Ctrl+Left/Right Move cursor left/right a whole word
Ctrl+Shift+Left/Right Move cursor left/right a whole word and select it
Ctrl+Home Go to start of document/webpage
Ctrl+End Go to end of document/webpage
Shift+Enter Insert single new line character

For a full list of Windows 7 keyboard shortcuts, go here: http://windows.microsoft.com/en-US/windows7/Keyboard-shortcuts