Adding a profile picture is easy and beneficial.
First, click your profile link in the upper right part of the page.
On the left side of the screen, you will see where your picture should be. Roll the cursor over it and you will see “Update Profile Photo” appear at the bottom. Click on it to view the options to upload a photo or remove your current photo.
Next, select “Upload photo” and select a photo from your computer. Then, click "open" to add the photo you selected.
You can do the same with your background photo, by clicking on the background behind your profile photo and completing the same steps as above.