Of course you can make the sign up google form as easy or as complicated as you would like. You would then generate the google form to populate into a sheets tracking grid so you can see who will be coming on which day. This is what you can print out for students to attend, or make it into a pretty graph!
Check out this example to see how it works >> http://bit.ly/workshopformsexample
Mrs Priestley ICT blog is a place to read, download and view ideas!