DigitalWebTalk

Forewarning:

“Premature optimization is the root of all evil.” — Donald Knuth.
…in other words, don’t implement in extra complexity if you don’t need it. A site handling a few thousand requests per day will do fine on a default configuration and just about any hardware. This article is geared towards a site that needs to handle [...]

First if all, I would like to Thank my friend, Qadir Menon for giving me these wonderful tips!

It really helped me a lot preventing ddo attacks which were really annoying me!
Basic Linux Server Security

Install Firewall (APF or CSF Firewall with BFD)
ModSecurity (Web application firewall)
ModEvasive (Prevent DDOS attacks)
Harden SSH server
Fix Open DNS Recursion
[...]