OS X is a bit retarded, but what the rest of the world thinks Home / End should do, Mac users can achieve by pressing Shift + Home / Shift + End or Control + A / Control + E respectively. I’m talking about how to move your cursor to the beginning or end of a line, of course!
If you’re on one of those special midget keyboards (a laptop?) that lacks useful buttons like Home and End, you’re probably looking for Shift + Fn + Left / Shift + Fn + Right.
There are a bunch of ways you can remap the key bindings, but in the interests of staying sane when working on others’ machines, it’s probably worth changing your muscle memory instead of your bindings here. It’s also worth noting that Vim users can use ^ / $ for beginning / end of line respectively.