There is a book Threatsaurus: Computer Threats from A to Z which I've found useful and explains the facts about security threats to your computers and data in brief, simple and easy-to-understand language. The book is freely available and accessible from the link above.
The book has four sections:
A-Z of Security Threats
Lists all types of threats in alphabetical order with a brief summary of what each threat is and how it can infiltrate your computer, data or network. From Advanced Persistent Threats (APT) to what a Zombie is.Security software and hardware
Identifies security softwares and what they do like Anti-Malware, Anti-Spam, Endpoint Protection etc. Also highlights on the security appliances, which are a combination of hardware and software security elements in one solution, like web appliances, email appliances, Unified threat Management (UTM) appliances etc.Safety tips
These are tips to advise on how you can be safe on the internet, secure your data, purchase online safely, avoid viruses, spyware, worms etc.Malware timeline
Shows a timeline of key moments in virus history. History of viruses, Trojans, worms and when they began to pose a threat.Everyone needs to be aware of the security threats to data, computers and networks to be safe.
There are many sources of news about information security and there are also plenty of free resources, written by journalists, security professionals and enthusiastic amateurs, where you can learn more even if you are new to the field. Security information can be found on news sites, technology sites, information security companies' websites, blogs etc.