The most important part of managing your personal digital information is to limit your exposure to various threats. These threats can also be called risks. Every computer system has vulnerabilities or weaknesses. These weaknesses may allow for accidental exposure to risk or for malicious exploitation, in either case these are things you want to avoid if possible.
Before getting into the core of your security management there is a security baseline that is a good starting point for most people. On your desktop computer there are several items that should be implemented. These items include turning on Windows firewall or installing a third party software firewall such as Norton Internet Security, installing an anti-virus and anti-spyware application (make sure they are being updated continuously), disabling Windows guest account or similar guest accounts in your particular operating system, and implement strong passwords (use numbers, upper and lower case letters, and special characters). For home based wireless networks it is recommended to turn SSID broadcasting off (but be sure to know your SSID name in order to connect) and use WPA or WPA2 encryption.
Wireless devices such as phones and tablets present a different set of security issues but in most cases are less of an issue to the average user. There are firewalls and anti-virus applications for many phones and tablets and anything that comes standard with your device is likely a good thing to implement. Encryption on your mobile device is probably the most important security measure to implement. Encryption will protect your information should your mobile device become lost or stolen. Most encryption will only be helpful though if your device is locked or powered off. Once your mobile device is logged on with your password then the encryption is bypassed until the system is once again locked or powered off. This reminds us that it is important to maintain strong passwords and never share passwords or write them down where they can be easily found.
Now the most important part of your security profile is based on your actions. Limit your internet surfing and you limit your exposure to various risks. Keep your PC or mobile device locked or off when not and use and you limit your exposure to various risks. Ultimately you must also decide what information about yourself is important and what isn't. If you have extremely important information then don't post it on the internet, send it in e-mails or share it without using extreme caution. Limit the chances of introducing risks by limiting the use of items given to you by others (such as USB drives) and synching your devices with systems you have no control over. Ultimately your personal digital security is in your hands and you have control over what information you choose to expose to potential risks.
One final note on security and that is to always have a backup of your important data. When (not if) you lose data by exposure to an external risk or simply a hardware or software failure then your only hope may lie in the hands of your backup process. Be sure to backup early and often and include a backup plan as part of your overall security implementation process.