First of all, as Salesforce admin, you need to enable this feature. Navigate to Setup | Customize | Work.com | Work.com Settings
Then, you also can enable more setting:
- Edit Skills and Endorsements via record detail pages
- Enable Suggested Skills
But, you are not always need to enable this additional features.
Once enabled, you will see a new related list under User detail, called User Skills. From here, you can add New Skill or New Skill User.
- this mean to create a new Skill with Description
- record prefix 0Sk
- object API name: ProfileSkill
New Skill User
- this mean to assign user with existing Skill
- record prefix 0SM
- object API name: ProfileSkillUser
Another related object is Endorsement
- this is represents a detail relationship of ProfileSkillUser.
- record prefix 0SE
- object API name: ProfileSkillEndorsement
On top of new related list under User detail called "User Skills", you will also notice Skill and Skill User added in the Profile: Page Layout, Field-Level Security, Tab Setting (for Skill only), Record Type Settings, and Object Permissions (Skills, Skill Users, and Endorsements). Make sure your users have the object permissions enabled to be able to view, add Skill and endorse other user.
Once Skill is enabled, user can go to their User Detail to add "New User Skill", or admin can add Skill for their users too. Once added, Skill it appear User Overview tab too.
User with Endorsement object permissions enabled will be able to endorse Skill of other users.
The same info can be seen from User detail related list too