The registration form asks for information that I’m uncertain about. Should I take my best guess or leave it blank?

You should complete all required sections of the voter registration form to the best of your ability. The problem with leaving portions of the form blank is that there are different rules in different states regarding what is a complete form and how to treat incomplete forms. You also have to attest to the truthfulness and accuracy of the information you’ve provided. If you have an idea but are unsure, write “to the best of my knowledge” next to a section you’re not 100% sure of.