I just started to use NetBeans, and am trying to work out how to:
Make it so that trailing whitespace is removed on save. I know that you can invoke it manually
For the first question, NetBeans 7.0+ has now a built-in solution. You can find it in:
Tools > Options > Editor > General > When saving files > Remove Trailing Whitespace: Never / Always / For Modified Lines Only
Tools > Options > Editor > On Save > Remove Trailing Whitespace From: None / All Lines / Modified Lines Only