On the simplest level a roster is a list of people. Functionally, the list serves to associate people with certain duties, which often also includes a time schedule.
For example, forr how to make a family chore roster see:
http://support.gateway.com/s/tutorials/index/Tutorials.asp?cat=1&subcat=1&topic=37&series=851
Other sites of interest that relate to rosters are:
http://unionsafe.labor.net.au/hazards/104787141324939.html
http://time.iguw.tuwien.ac.at/nov2000miniB.htm
http://www.shiftwork-resources.com/
http://www.shiftwork.co.nz/12hour.htm
http://www.osh.govt.nz/order/catalogue/pdf/shift-p.pdf
http://www.asap.cs.nott.ac.uk/publications/pdf/GarethThesis.pdf
http://www.few.vu.nl/~sapot/call-centers/Shift-Scheduling.pdf
