The next question is what type of guest book should you have? There is not 'one style suits all' for this.
Think of you and your partner, your lifestyle, your loves and also your wedding. Is there a theme running through such as the ocean, music, football, family?
If it's the ocean, have everyone write their messages on a vintage surfboard to varnish and display, or shells to collect and display in a jar, or messages to put in a bottle for reading in the future.
With music, supply some blank sheets ready for musical notes and let everyone get creative - or ask them to sing you a message to camera instead!
Football... Have a football passes around the room with a pen, make a team photo and have everyone write a message over their pic, or how a out a wall of paper football shirts for everyone to logo and name?
Be creative, have objects to sign then frame or varnish. If you embroider, have them sign a table cover that you can later embroider and keep or why not supply a Polaroid camera and ask them all for a mugshot!