this is probably more for the switchers out there and my own personal reference, but if you like your home and end keys on your mac to go to the beginning of the line and end of the line, this is what you need to do:

system-wide home/end:
Make a file ~/Library/KeyBindings/DefaultKeyBinding.dict

{
"\UF729" = "moveToBeginningOfLine:"; /* Home */
"\UF72B" = "moveToEndOfLine:"; /* End */
"$\UF729" = "moveToBeginningOfLineAndModifySelection:"; /* Shift + Home */
"$\UF72B" = "moveToEndOfLineAndModifySelection:"; /* Shift + End */
}


that makes system-wide changes to your keybindings EXCEPT in firefox. to fix it in firefox, use this add-on:
Keyfixer

and now you have happily “working” home/end keys.