Can someone give me simple advice on creating an E book?

[Mr Coconut]

Hi. I have a subject that I am passionate about, and gets a lot of attention when I discuss in on the internet at large. I have written for some time, on forums and so on, and what I would really like to do is put all of my thoughts and research on my subject into one book, then make that freely available to as many people as I can, on the internet. I don't really want to go down the route of trying a conventional publisher, as I want my work to be seen, and not for that to be at their mercy. I did look at some self publising sites, but they seem expensive, for what you really get. I know there are a few YT vids out there, showing different ways to do an E book, and wondered if any of you had advice you can give? I am not incredibly technical, so keep that in mind :-). I do not have a blog at the moment, is there a means, having done the E book, that would best get it seen online? Is it possible to even sell your E book, and how would you go about that? Thanks