Access a website, like Keep and Share or Formville, as two examples, that allow you to create your own sign-up sheets. You will most likely need to establish a new account with these types of sites. You can also design a sign-in sheet with Google Docs.
Select the option for a new document and choose the template you wish to use. Edit the text from the template to match your needs. Once completed, you can decide who has access to the sign-up sheet and you can email links to it to the people you are trying to recruit.
Create a sign-up sheet with pencil and paper if the online option does not appeal to you. Write the name of the event across the top of a sheet of paper. Make blanks for people to sign up, using at least two columns, more if needed. You can break the blanks up into sections in necessary (like salads, desserts and main dishes for a potluck.)