VPS Security :- First things first !

Hi all, 

I have gone through some very useful information in this forum. However as an amateur when it comes to VPS security, I seem to not even know what all I don't know yet or am missing about VPS security. I think it would be great if the information can be compiled, by the experts, in a linear first things first manner, to configure a VPS for security. That would be soo much help. 

Thanks all