KEYBOARD SHORTCUTS full list from Autodesk
https://s3-us-west-1.amazonaws.com/help-dev.autodesk.com/v/img/59899_2013_Keyboard_Shortcut_List.pdf
FAVORITE TIPS TO KEEP YOUR MODEL SPEEDY
click here for all 10 tips from Payette
http://www.payette.com/post/664154-ten-ways-to-keep-your-revit
33 REASONS WHY YOU CAN’T SEE IT
click here for full post from The Revit Blog
http://www.therevitblog.com/2013/04/cant-see-it-in-view-heres-33-reasons.html