The best thing is to find a host that will manage a regular backup scheme for you - It will cost alot more than regular hosting but it will be worth it...
A few things you may want to investigate is how they backup - If they backup to the server your site is already on, there is no point
Ideally the way they back up your data is by mirroring your site(s) at a particular point in the day to at least 2 seperate servers
Chris