Step 1:
Log in and scroll down to Account & Settings. Click "Profile Information"
Step 2:
You can then change your Cover Photo, Avatar and add a Bio
Step 3: a)
Changing your Cover Photo. Click the pencil icon on the Cover Photo section
Step 3: b)
Changing your Avatar. Click the Select A New Photo button
Step 3: c)
Add a Bio - type in the Bio text field to add one.
Step 4:
Click Save