Using notes
The task outline and the resource outline both have a Notes column, which you can use to store extra text about any item.
To edit the selected item's note, press Command-', press the Enter key, or click the Note icon 
in the Notes column.
in the Notes column. Once an item has a note, you can move in and out of the note field by pressing Command-' (which hides the note after you stop editing it) or Enter (which leaves the note open).
The font style of notes can be set up in the Project Styles inspector.