Imo you can play however you like, without getting exact instructions like "cast this and that and then this again".
Try and see what suits you.
I prefer SBs spam, somebody else might like dotting/draining.
I think you have plenty posts here about spell rotations, plus quite informative stickie. Take some time and read around a bit and then go out there and try to see how does it fit your personal play style.
That said, if you are 70 and want to leave good impression on some group you run instances with, just throwing few DoTs and heal your pet will soon get you to the bottom of damage meter.
There are certain talents that are imperative if you want felguard and if you want it to be the best it can.
Read around, check different builds, decide how far demo you want to be.
Read stickie.
Play as demo for few weeks and then come here and ask questions.