The look of your book doesn't so much depend on the tool you are using, but on your background knowledge. A design pro could use a glorified text editor and still make a better layout than a novice working with InDesign.
The topic you are looking for is known as "desktop publishing", abbreviated to DTP. And yes, the learning curve of LaTeX is steep, but the effort of learning how to do DTP with LaTeX is negligible compared to the effort of learning what you need to do for the book to look good.
If you really want to learn, use this manual for LaTeX: http://www.ctan.org/tex-archive/info/beginlatex/beginlatex-3.6.pdf. It is free, and LaTeX is also free. It won't teach you how to make beautiful designs - for that you need first some talent and second quite a few experience. But it will teach you the technical side. There you'll also learn what kind of problems you must learn to solve if you're really serious about DTP. (Example: what to do if your automatic page breaking leaves a single row on a new page, followed by a heading?). And don't just read it and try to memorise it, or just do the small exercises there; make a project of sufficient length (maybe 7-8 pages of text) and then try to apply everything you learn. Then you'll have enough technical background to create any layout you wish. Your only constraints will be your own taste, talent and imagination.
Of course, there are many other programs for DTP out there, but the ones which can really do something also cost several hundred dollars. And just because they are WYSIWYG it doesn't mean that making a good design with them is easier. It is certainly quicker, if you're a pro, but you obviously aren't. LaTeX is free, open, compatible, and in some fields (especially academia) a quasi-standard. Besides, the manual I can recommend is meant for LaTeX ;)
Wish you good luck!