MITA is shit. I'm almost finished a mechanics apprentiship, will be glad to get away from MITA. Thats my personal opinion, although I will admit I wont be where I am now if it wasnt for MITA.
Best way to learn is to study, study, study, research as much as you can, then go get your hands dirty. Remember where everything goes, take photos of how it all goes together if necessary, and keep in mind shit only goes back together one way! My first engine swap was in a small dusty shed in Chittering, managed to do it all myself. And I'm not entirely the best mechanic around, in fact the sooner I get out of this industry the better, but it just goes to show its not overly hard when you put your mind to it and jump in head first.
Best of luck mate!! The Skyline is a good car to work on, not too hard. Just dont try and do coolant hoses other then top and bottom hose. You WILL go crazy!!!!! Worst thing I've ever had to do...