I was pretty much in the same situation when I started this hobby two years ago, so I am certainly no professional.
This site helped me a lot: http://www.clockmaker.com.au/diy_seiko_7s26/ This is the best free source of structured information I could find so far, together with Esslinger and Mark's video of course... can't wait for his lessons to start later this month by the way !
I spent some time in Seiko modding, there are tons of sites about it. Thanks to these, I now feel confident enough to invest in more expensive parts in order to assemble my first ETA based watch later this summer.
About books, I found most of them too advanced. There is one that provides a great deal of background information about watch assembly: https://www.amazon.com/Beginner-Watchmaking-Build-First-Watch/dp/1456451650
True watchmakers will find this book ridiculously easy and sub-quality, but hey, we all need to start somewhere !
Last but not least, I started with inexpensive Chinese and Indian made tools. Over time I got them replaced by German and Swiss made, as I realized how important the tools quality is in terms of reliability, accuracy, comfort...and therefore learning curve !