If you are writing code, you are doing yourself (and anyone using your code) a disservice if you do not read something on secure coding. There are not a ton of code agnostic resouces, but you may want to start with "Software Security: Building Security In"

I would then look for language specific options as well, because programming for security can vary a lot amongst languages. Writing securely for native applications running on a system is much different than writing secure web apps.