After logging in, from the home page, click on "Account", then click on "Add Additional Users to Account". From there you can click on "Add User". You can choose whether to add a Basic User or an Admin User. Basic Users cannot add additional users, only Admin users can add other users.
How do I change my password?
When logged into your account you can change your username and password from the Account section of the website. Once in the Account section click on the "Current Login Credentials" and then click the "Click Here to Update Username and Password".
From there you'll be prompted to update your credentials. Your current password is required. If you don't know your current password you can recover that from the login page.
Multiple Users Online
In order to have more than one user logged in at one time you'll need separate accounts and you'll need to be on different browsers. We originally set this up to avoid people over writing each others orders. The way around it is the separate users on different browsers. Example: user1 in chrome and user2 in Firefox.