If promotion means "how to get higher in search engine results", then you don't need to read any special literature. There are two types of factors in SEO: internal (working with the site itself) and external (links to the site, their quality and quantity). The importance of internal ones is constantly growing, it used to be important to be linked to, and it doesn't matter who (that's why people bought links, created fake sites specifically for this and did many other bad things). So, now, if we are not talking about highly competitive requests, it is enough to make a normal site: correctly register keywords, arrange headings, have normal text, signed pictures, optimization for mobile devices. How to do it right - just search in Google for something like "10 steps to optimize sites". It is also important that people use the site: read it, look, do not leave immediately after opening. And you need to be patient, indexing and its changes take a long time, weeks, months.
For starters, I would recommend the Google Search Engine Optimization Quick Start Guide. Free distribution. In general, just make sites for people, if users come to them for targeted requests and share materials from them, for a search engine this is a sure sign of the resource's usefulness.