Don't even think about partitioning. If you do not have backup, partitioning is way over your head (not trying to know you, but if you have no backups, indexes, etc., partitioning is the least of your problems).
Once the dust settles, get a valid backup strategy in place. DBAs get fired for not having valid backups. If your company says they can not afford the space\resources to backup the data, then fight them. Get it in writing all the way up to the CIO level. Make sure that they know, without ANY doubt, that one bad disk sector can take out the entire database. And disks fail, or sometimes hiccup to the point where a database can be corrupted.
Take a look here: http://www.brentozar.com/needs/