Which best practice involved in software configuration management to help in improving project management?
Assuming you're really focused on best practices, I can outline a couple of possibilities.
Using the best (SCM) tools available. While this might depend on your specific goals and constraints, Mercurial and Git are hard to beat (distributed, excellent branch/merge capabilities, multiplatform, FOSS, really fast, flexible workflow etc.).
You can analyse the data in your source repository using a tool like PanBI (disclaimer: I wrote it). A short screencast shows off what you can learn from repository contents analysis. In brief:
...and much more.
Connecting an SCM tool with an issue tracker can also add value. Developers place issue ID's in commit messages, e.g. "[#1455]: improved performance a bit" and the issue tracker relates the issue with the changes in the code repository. From a project management perspective, this allows you to loosely track the time spent on individual issues, project phases or complete projects. A simple commit hook refusing commits without an issue number can go a long way in ensuring data consistency. Such "measured" data can be compared to the baseline to understand what's working and what isn't.
Building official releases on a build server from a tagged source version pulled from the repository could also be considered beneficial from a project management perspective because it's a way to control quality. Building software this way detaches the build process from any dependencies or specifics of developer machine environments, provide reproducibility, allows robust automatic/semiautomatic publishing of the build etc., i.e. streamlines and shields parts of the deployment process.
These are just some of the possibilities, it doesn't stop here.