There are no rules, or special format to discover local History
The only way I know, is to read all the books (don't assume they are all true and correct either), beg, steal or borrow maps and documents from anywhere, study them, and study them again. Google Earth is your best friend, so are the 25 inch/mile OS maps, the older the better.
Go to talks that are held in the area (mine are excellent - not - LOL !)
Ask yourself (and as many people as possible - the older the better !), WHY - WHY - WHY. And - don't assume that anything anyone ever tells you is true either, especially from the war. They may have been told mistruths and lies - they almost certainly were, but there is usually a grain of truth in there somewhere. People are frequently really keen to tell you what they know. Don't forget as well - older people tend to die - they may be gone tomorrow and you will never know.
Go and see things on the ground, how the **** anyone can understand anything without seeing it on the ground, even if it is just a field, I don't know.
Then, go back and challenge everything you have seen written or said and form your own picture. It takes years, but it's worth it. After a while, you build up a circle of friends and sources, after that, the info comes pouring in - sort of.
I personally find that it is impossible to know everything, so you have to specialise in distinct area, mine is WW2 and Coal Mines.
I should imagine that with tuition fees at £9k a year, that there are going to be few degrees around in the subject now.
An example is the brick sheds near the M56 at Helsby. I was told they were built by Italian PoW's in WW1. They were actually built by McAlpines in WW2. A grain of truth.
If there is anything you want to know, please ask me, but remember, I'm far from being an expert.