To add pictures to your account, Go to the photos application:
https://www.facebook.com/photos/ (to get there, click on the "photos" icon on the bottom bar, or search for "photos" in the search field".
Then you will have to make a album (ie. click "Create a photo album " button on the top right).
Enter the information (ie. location, name, etc) it asks you for.
After you make the album, you can upload pictures to it. Simply click "Add photos" in the album that you created. Or, in the future, click on an existing album and you can add photos to it as well.
There is a limit of 60 pictures per album, but you can have unlimited albums.