The idea of software configuration management is that of monitoring and controlling changes in the software. The baseline is the standard and formally accepted form of a software item that is meant to be configured. It is like a generally accepted reference point, which could be applied in effecting incremental changes in the software.
There are three types of baselines which are the functional, developmental, and product baselines. Functional baselines provide an overview of the functionality and specifications of a system. The product baseline encompasses both the functional and physical details of the system.
It really depends on your type of data, if it's sensitive data or not. And it also depends on what type of backup (Incremental, Decremental, etc.). But you should aim to backup at least once a week, and also do a backup of your original backup.
