Add New Blog User
1.) Go to Users -> Add New
Click Users on the left hand menu of your Dashboard and then select Add New.
2.) Scroll to the Add New User Section and Fill Out the Details
You may need to scroll a little bit to get to the Add New User Section.
Once there you'll need to enter the username, email address and the users access level. When done hit "Add New User" and an email will be sent to setup their account.
If allowing Administration access please ensure you fully trust the user you are adding as they will have full access to your website.