Click the Query Skills link to search for the skill(s) you want to assign to this person, then drag one or more skills from the search results onto the Skills topic.

You do not need to do an explicit Save after dragging skills onto the Skills topic.

or

In the next available row, enter the name of a valid skill and click the Save icon at the end of the row.

The name you enter must match the name of an existing skill. Clicking Save in this case both validates and saves the skill.