1: Open iPhoto
The first time you open iPhoto ’11 it will automatically scan your library for faces. The bigger the library the longer this will take.
2: Click on Faces
Click on the Faces tab on the left and you are taken to a corkboard where you can see identified faces. Click in the name fields to add a name to each one.
3: Continue to Faces
Click Continue to Faces to go to the main wall. Click any person, looking at the bottom-left to see other possible photos of that person iPhoto has found.
4: Confirm faces
Click on Confirm Additional Faces to review any faces and select those that are correct, or click again to reject incorrect matches. Then click Done.
5: Add more faces
From the toolbar at the bottom-right of iPhoto, click on Find Faces and any new or untagged pictures will be shown. Reject, or add names as appropriate.
6: Quickly preview faces
From the main wall, move the mouse over any Face to see all pictures of that person in sequence. Hit space bar on any image to make that one topmost.
7: Manually add a face
If iPhoto has failed to identify a face, you can double-click the picture and hit the Info button. From the Faces tab on the right click Add A Face.
8: Tag the person
Drag the resulting box over the person’s face. Click to add their name in the name field. Hit return to tag. Click the arrow to see all pictures of that person.