Lists are easy to create, and it is even easier to add users.
Step 1: Click on the "me" icon on the top of your Twitter home page.
Step 2: Select "Lists" in the box in the upper left hand corner.
Step 3: Select "Create list."
Step 4: A new window will open. You can enter the name of your list, a description (optional), and indicate whether the list is public (anyone on Twitter can follow the list) or private (only you can access the list).
Step 5: To add a Twitter user to a list, select a user, then select the downward arrow on the icon on the right. Select "add or remove from lists" from the pull-down menu.
Step 6: You can then add a person to a list by selecting the empty box next to the desired list. A checkmark will appear in the box. Then, close the window to save.