Why not subscribe to some western hunting magazines and get some good info in every issue? Eastmans, Western Hunter, Elk Hunter, Extreme Elk, and Bugle, to name a few, all have good articles in every issue.
This book should be required reading by every one who hunts elk. It is a massive book that will offer days, weeks or months of reading to learn all you can. It's a spendy sucker, but if you want information this is where it will be.
The original edition is a classic, but it is now available in an updated form reminiscent of a large university-level text book. On Amazon I think it was over $170.00. I am a member of The Wildlife Society and they sell it as well from their online store, but I think you need to be a member to access it.
I've got Elk of North America, Ecology and Management, 1982 edition. I don't know how many times I read it, cover to cover, back in the 80s. Good book. However, I do agree with Southern Elk's post: get the monthly or quarterly magazines and soak 'em up. Some guys are FOS but you can still pull an elk pellet out of some of their articles. Other articles are great.
My father was not a hunter. I'm "self-taught" since I was a little boy, drinking up Field and Stream, Outdoor Life and the like. Magazines are a good resource and most of what find in books will end up in the articles and the other way around.