Some sites to help you with Excel work
http://www.cent.org/geo12/org1c3.htm
http://homepages.westminster.org.uk/it_new/ecdl/mod4/mod4.asp
http://www.juicygeography.co.uk/excelres.htm
http://mason.gmu.edu/~klargen/111labpopulationpyramidsspring04.PDF
http://geography.about.com/gi/dynamic/offsite.htm?site=http://www.census.gov/ipc/www/idbpyr.html
http://geography.about.com/library/weekly/aa071497.htm
Pivot Tables for Fun (?)