Click on the Save Preset button if you want to save a Sketch and Toon material for later use. A small window will open in which you can enter information such as name, author, etc. for the preset. The preset will be saved in the Content Browser under Presets/User/Sketch Material. Clicking on Load Preset will display a list of all presets, which can simply be selected by clicking on them.
Look up Self-Blend.
The Notes box is a place for entering notes about the material.