Welcome aboard!
Actually, I think the K-3 isn't the best camera for a beginner. My K-5 would be much better, so I suggest we swap!
OK, congrats on getting one of the best cameras on the market! As the Scotsman said above, get out there and take lots of pictures. Get out of Auto mode, experiment with different apertures, learn the limits of the camera. And have a look at what shooting raw format can do for you. I find it indispensable.
Enjoy, and do use the forums! Lots of friendly and resourceful people here