Variables are entered as (FieldLocation.FieldName), with the open and close bracket on both ends, and the period in the middle. The FieldLocation can be Profile, Lead, User, or CallLog. The FieldName is the name of the field you want to get information from. For example, to get the first name from the profile, the variable would be (Profile.First Name) and would then insert the text found in the "First Name" field in the profile into the script. After using variables in a script, make sure to open a profile and check that the variables are getting the right information.