For finding guides and videos - just search for {thing you want to setup} setup guide, there are plenty of results for almost everything. Also, I then showed links to where to setup readarr and qbittorrent.

The only thing you need to get up and running is the OS specific guides (windows is download, run the installer, go to localhost:8787 in your browser, and macos is similar. Linux is a bit of a mess, and I would recommend going the docker-compose route if you are on Linux instead) which are short and tell you every step. The reverse proxy is just a recommended guide for setting one up if you want to access it outside of your network - I don’t recommend doing it, and it’s not necessary at all (I don’t have that setup, all of my stuff is only accessible on my local network)

For finding books, use the readarr quick start guide - it goes over how to use the app, how to add authors and books to grab, etc. I also found this guide that appears to show how to do all of this including the install guide, adding authors and books, connecting to your torrent client, adding indexers, etc: www.rapidseedbox.com/blog/guide-to-readarr#05