Just got a question on noise removal so I thought I would write up how I do it. This will not work in every situation but it is a fast effective solution for what I need.
Down and dirty hiss removal.
Here is what I do.
After opening or recording a sound file you may notice small sound waves or hear an audible hiss.

I select a small portion of "noise" but nothing that I want to keep.

Then on the menu bar click Effect and then Noise Removal.
In the popup click "Get Noise Profile".
Then click Edit and Select All.
Click Effect and Noise Removal again. This time click Preview or Remove Noise.

If needed you can adjust the slider level to remove more or less noise.