Go to create or edit the development goal page. Then go down to the line "Focus skills" (see "How to create Development goal for team member?").
Tasks are added to previously added skills. In order to add a task click on the plus sign.
You can write specific tasks within the skill, you also have an opportunity to frame tasks into the checklist. Add materials that will be needed for an employee. You can add them from knowledge base, recommended materials or upload it from the computer.
Set a deadline for each task.