I have to agree with phish on the book thing. I too am new to the whole networck security thing and got myself a copy of hacking exposed it is an excellent book for people on either side of the fence. They tell you indepth the hacks that are commonly used to get into various servers and computer types and counter measueres to avoid people from using it on you. however I must say that at some points it is rather annoying for them to say the same thing over and over again.