Just wondering on whether to capitalize the chapter headings of my book totally including words like 'the', 'in' etc?
absolutely not... look up the rules for capitalizing titles and you'll find that will not be correct... you should be able to tell that just by looking at book titles on your own bookshelf, or on amazon... that said, such words would naturally be capitalized if the first word in the title...
I probably wouldn't capitalize articles except the first one. But chapter titles are partially a style choice. Browse through a stack of published books if you want evidence. This source is a bit more thorough than dismissing the question with an absolute: Rules for Capitalization in Titles For more examples:
This is so bizarre. I edited this post a half dozen times to get rid of the extra quote code it keeps reinserting. But when I last left it, I had successfully fixed it. Now I go away and come back and the unwanted code is back. Now I started to edit it again and accidentally deleted the wrong thing so I cancelled the edit, but when I open the edit box again in has the draft with the erroneous deletion. This forum software is beginning to suck more than it has some nice features.
i agree, if the op is asking in order to style his/her self-published book... my comments were aimed at how to do it in a ms that will be submitted to agents and paying publishers...