User/device CALS

I have a pretty dumb question but our IT guy left and we need a new server. We are looking at SBS 2003 we have a total of 12 users that will access the server and we have a total of 21 computers and 5 network printers. I know we have to purchase cals for each user but do i have to purchase a cal for each of the computers and printers the users will be accessing. For example if I have 10 computers and 5 people that will access those computers and one printer do i need 16 cals?

Thank you