I agree with Dave, at one time you had contributers to magazines who explained how they built their models. You would get hints and tips on scratch building, even full articles. But of late it appears to be box donated, open box, throw in paint, close lid, shake, open box, throw in filters, pigments, wash - yawn, yawn, yawn - you can learn more from just a few modelmakers on the internet, than you can from model assemblers who ALL follow the same trend, at one time modellers used to come from a diverse area of finishing and subjects, now it is though they came from the same womb. I spent my money on those books that tell you how to do it, dvd's the same - should have spent my money on sweets and grown fat.
For example and here the internet is at fault as well - 3D printing - Yes they cover the unboxing, setting up and the all of a sudden there they are printing off items. My questions would be show me how to produce the drawings, what do I need to know apart from "just download this cad program and it will even make your tea and buscuits", and then how do you get the file from the computer into the 3D printer - no one caters for the absolute beginner, and it is the same with modelling.
I am sure there are modellers who would love to be informed even on this site, how do you do that, but are a bit shy to ask - but that is what we have that little envelope for next to our name. Please use it, and you will find your answer.
As for magazines, the paper variety and some other 'forums', save your money and time, find a good forum and use it.
And like Dave I go to competitions and look at the models on display at the club stands and can see the efforts put in, and then look at those in the competitions and see the expertise.
These are my views and you may not agree, but let's not start a long drawn out debate. I will not be answering points I have made mine.