A best Backup stretergy

i was hoping if anyone enlighten be with a best backup stretergy ever for small business with about 30 employers an exchange server 2003, plus finance applications, file server and about 20 pc on our LAN.we currently have a backup tape drive attached to our main exchange server but if anything happens to our office(burn down or…)all our data will be gone.
any softwares anyone that can be our life saver if a disaster strikes?

Thanks.