Small Business Server is NOT R2 - so you have to schedule it with a bat file.
Here is a script inspired by this page. I put it as a scheduled task. It writes to a log file, then does the backup to that log file and makes an end to the log.
It adds a time stamp to each backup.
rem
rem
rem get the date and time without the slashes and colons. Note if I echo date and echo time I get dd/mm/yyyy and time is hh:ss:mm.ms
set filea=%date:~6,4%-%date:~3,2%-%date:~0,2%_%time:~1,1%%time:~3,2%%time:~6,2%
rem now start the log file
echo ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> E:\GeekCentral\scripts\results\backuplog_%filea%.log
echo %date% %time% %username% start >> E:\GeekCentral\scripts\results\backuplog_%filea%.log
rem
rem - make a place to put the new backups
rem - note that I have a drive mapped to a shared folder "GeekCentral" so if I went to \\sbs-server\GeekCentral I have a folder there
rem that has the drive mapped here - and to my f: disk.
rem - see http://technet.microsoft.com/en-us/library/cc753321.aspx mkdir "e:\GeekCEntral\BackupMount\Backup_%filea%"
rem
rem - now start the backup - see http://technet.microsoft.com/en-us/library/cc742083(v=ws.10).aspx and
rem webpage http://social.technet.microsoft.com/Forums/en-US/windowsbackup/thread/1ab34447-4e81-4589-8aa1-8275cff132fc/ rem
Wbadmin start backup -backupTarget:\\sbs-server\geekcentral\BackupMount\Backup_%filea% -include:C:,E: -vssFull -quiet >>E:\GeekCentral\scripts\results\backuplog_%filea%.log
rem
rem - end the log file
echo %date% %time% %username% end >> E:\GeekCentral\scripts\results\backuplog_%filea%.log
echo ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ end >> E:\GeekCentral\scripts\results\backuplog_%filea%.log