I thought the internet was created so that we wouldn't need books any longer?
Well, e-books would qualify as books in my view.
I guess what I'm trying to say is that if the OP is asking such general questions on an internet forum, it can mean that he simply is not ready to undertake the task of thoroughly securing his server.
So my general advice would be that he document himself about the general principles, the different security layers, understand all the trade-offs and design choices that impact security and come back with a solid plan.
The OP seems to have interesting ideas (on which I already commented) but a serious lack of experience. Lacking experience is allright as long as you know it and have the brains to think for yourself.
Two general security principles :
- You can't have your cake and eat it too, there is *always* a trade-off between security and convenience, no exceptions.
- Don't code security-related stuff yourself, someone has probably already done it, and done it better than you. Use libraries as much as possible, not fancy ones, but mature ones. Don't hand-escape SQL, don't hash passwords yourself, etc. You get the idea.