From personal use

  • Ctrl+e : using seam to create UV maps
  • Collada / .dae import unavailable in 2.72 (Debian)
  • bb : square visual vertices selection
  • click+shift-click : selecting one vertex and the next
    • useful to merge them and close a gap
  • shift+a : add
  • Delete-Enter : delete selection

Note

My notes on Tools gather what I know or want to know. Consequently they are not and will never be complete references. For this, official manuals and online communities provide much better answers.