enter different modes:

• i :insert
• v: visual
• shift+v :visual line
• control+v :visual block

quit different modes:

• esc : quit insert
• v :quit visual
• shift+v :quit visual line
• control+v :quit visual block

quit & save

• :q :quit
• :x :quit and save
• :q! :force quit without saving

undo & redo

• u :undo
• control + r :redo after too much undo:

move the cursor

• h :left
• j :down
• k :up
• l :right
• fX :pressing f and X together moves cursor to next 'X' in the same line (X is any character)
• ; :repeat fX in same direction

search

• :/text :search text
• n :next matching
• N :previous matching
• ggn :jump to the first matching
• GN :jump to the last matching
• :/<text> : search your exact text
• :^text :search text at beginning of one line

write lines to file/clipboard

• :1,2w filename :write line 1-2 to a file
• set clipboard=unnamed :add to .vimrc to share the Mac clipboard with vim
• :1,2w !pbcopy : copy line 1-2
• :r !pbpaste :paste the clipboard

references:

1. Vim最少必要知识
2. Vim基础-Markdown语法练习
3. All the right moves
4. Mac OS X clipboard sharing