An instructor may want to create a sign-up sheet to allow students to sign-up for office-hour slots, or to sign-up for topics for an assignment, or for meetings with an advisor or conference seats, etc.
The best way to accomplish this is to add a Wiki to your course. A Wiki is a page or set of pages that can be viewed and edited/filled-out by students.
Create a sign-up sheet on the first page of the Wiki with visible slots that the students can sign-up for. The students can then come and sign their names in the slots by editing the Wiki page.
Example of the content of the Wiki:
Sign-up for Office Hours on this page. To sign-up, select “edit” on the right, and add your name to only one slot. Slots are taken on a first-come-first serve basis: