general commands:

• :w - write file to disk
• :w! - write a readonly file!
• :wq - write and quit
• :q - quit vi
• :q! - quit without saving

• :set number - line numbering on
• :set list - displays all characters
• :set ff=dos - fileformat ; :set ff=unix
• :set encoding=utf-8 - set file encoding character set

• :split - split the window
• :only - display only one window
• Ctrl+w+w - goto next splitted window
• :help nolist - online help about nolist

jump / search commands:

• n - jump to next search match
• N - jump to previous search match
• <n> G - jump to line <n>
• G - jump to eof
• :1,$ s/pattern/new/g - substitute form line 1 to eof

block commands:

• Ctrl+v - visual mode
• :help CTRL-V-alternative
• zf - fold marked area (with V)
• zo - open folding
• zc - close folding
• zd - delete folded area markers
• :help folding

editing commands:

• i - insert mode
• I - insert at beginning of line
• ESC - end (insert) mode
• A - append at end of line
• . - repeat last action
  
  
• r - replace character
• R - replace till <ESC>
• s<n> - substitute n characters
• x - delete character
• cw - change word
• dw - delete word
• d - delete line
• yy - yank line
• <n> Y - yank <n> lines
• p - paste line
• o - new line above

file buffer commands:

• :e - load new file in editor buffer
• :ls - list file buffers
• :b n - switch to next file buffer
• :b p - switch to previous file buffer
• :b <TAB> - switch to "selected" file
• :bd <n> - delete (close) file buffer n