Properly managed you can improve data integrity greatly. On the other hand, your data have never been in more danger. We have all come to rely heavily on computers, even more than we may realize. One of the first ways to safeguard data is to back it up. On a personal PC, backup can be fairly simple.
Networks multiply the problems.
This book goes into great detail about backing up a LAN, the media and the methods needed for this complex task. While it is thorough, it is not overly technical. This book is not the only book you would need but it definitely points you in the right direction. Next in importance is archiving, or long-term storage of data. There are a number of reasons for storing data in a safe place away from your normal place of business.