MojoMotor runs in your web browser so you'll need to login to edit your stuff. You'll access the editing mode by visiting a special URL, or you can have a handy login link on your site (which you can turn off if you want).
The admin toolbar
Site administrators have access to all admin toolbar functions as well as editing content. Site editors only have access to edit existing pages (they cannot create new ones).
The MojoMotor toolbar displays whenever you're logged in but you can easily switch to "view mode" to temporarily hide it while you preview your site.
Adding extra logins
You can set up as many administrator or editor logins as you need. Most of the time you'll probably only need one login but it's nice to know you can add more if you need to.