How to add attachments in the contact editing window:
Click on Add attachments below Attachments.
Select one or several files.
In order to remove an attachment, click the Delete icon.
Tip: You can also add an attachment by dragging and dropping a document from a file browser or from the desktop to the contacts window.
Also see
Creating a new contact
Creating distribution lists
Adding a contact from vCard
The contact editing window
Parent topic: Adding Contacts