If you want to start with TeX, I highly recommend the book A Beginner's Book of TeX by Seroul and Levy. One of the developers behind LuaTeX also strongly recomm

If you want to start with TeX, I highly recommend the book A Beginner's Book of TeX by Seroul and Levy. One of the developers behind LuaTeX also strongly recommends it (in the preface to the ConTeXt manual), and calls it "the book that turns every beginner into an expert". This one is more readable than the TeXbook, and builds up your intuition nicely. Learning LuaTeX is relatively easier after you understand the basic design of TeX.