There's tons of guides on there lol, so I don't know which one in particular you're looking at, but yeah they're all pretty much good lol.
My case is sitting at 28C right now, don't know if it is for you, but it's starting to get hot here these days.
As far as CPU, 40 idle doesn't tell me anything, really need to know load temp, if it's hitting 55C then yeah you need better cooling before you OC.
Idiotec - you dun need 'pretty pictures' This is computer geek stuff maaaaaan! It's gotta look all sophisticated and complicated to scare away n00bs