tar cf backup_dir/www_backup.tar www/html
mysqldump -uuser -ppass db_name > backup_dir/database_backup.sql
tar cvjpf backup.`date +%a`.tbz2 www_backup.tar database_backup.sql
cp backup.`date +%a`.tbz2 /windows/share
.. which will end up storing the last 7 days of backups & continuously overwrite anything older than 7 days. Why? because "date +%a" returns a weekday, so the backups will look like backup.Mon.tbz2
it also has the nice side effect of sending you a mail every time it's executed as that last tar is verbose & output from a cron script usually gets emailed to the owner. This is a good way of verifying everything worked.
The type of shell doesn't matter... could be bash, tcsh, sh, whatever you're most familiar with.