System Security (files and database)

 We are in the process of fixing our system security because basically everything is on default - application, file and database levels. I was able to acquire data on how to make the application more secured through the system profiles.  I need data on file security (basically a software or procedure on how we can control read/write and versioning of files) and on database security (primarily on how can we know if data has been compromised manually or if priveleges can be controlled by userid).

I hope the experts can recommend good research materials for our issues.