Here are some common keyboard shortcuts. For key combinations, press the first key, keep it pressed down and press the second key. Then "let go" of both.
WinActivate Start Button. Then use Arrow Keys, Space and Enter to navigate within Start Menu
EscClose Start menu. Can be used to close some popup windows. )
Win + EStart Windows Explorer
Win + DMinimise all windows to show desktop
Ctrl + Shift+ EscStart the task manager
Shift+Click on a taskbar itemOpen a new instance (copy) of the item
Win + TabShow All open programs. Click on the program you want to switch to, or press Esc
Alt + TabSwitch between windows. Keep Alt pressed and press tab to switch between programs
Alt + F4Close the window - if this is the only window in the program (often it is) then the program closes

In a document (Open office, e-mail, notepad)
Ctrl + ASelect all text
Ctrl + Ccopy selected text and put in clipboard
Ctrl + Vpaste contents of clipboard
Ctrl + Xcut (delete) selected text and put in clipboard
Ctrl + ZUndo last change

Function Key
On the laptop keyboard there is a key situated near the bottom left that is marked "Fn" in blue letters. This can be used together with the function keys that are at the top the keyboard (marked F1, F2 etc). If the function key has a blue icon (for example a speaker symbol) then pressing the "Fn" key at the same sose