There are many aspects of information security, to say the least. There's cryptography, infrastructure security, cryptography, operational security, etc. These are more network-based, and there are loads of information on these both in print and on the web.
But if you want to learn malware removal specifically - since that's what we do here - it's slightly easier. I suggest you hang out around at security forums, especially Wilders and DslReports:
Wilders Security Forums - Powered by vBulletin
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If you want to join the security team here at PCHF, then you will have to graduate from
one of the many training academies around on the web, or show that you know your stuff (HijackThis log parsing and general malware removal)
A very good 'training school' is:
MalWare Removal :: View topic - Malware Removal University - Now Open