Given the extra clarification, and still somewhat subject to opinion:
Dead simple tutorials: Eglen's A short example of how to use LaTeX for scientific reports (4 pages printed, 4 files to download, covers basics of tables, graphics, equations, citations, etc.), the LaTeX Wikibook (may not be the best possible document, but extensive and easy to get started with).
Adding a heading should be in either of those, or any normal tutorial. Changing the style of a heading is normally a bit further along in people's learning curve, but often involves the titlesec package. If you search this site for 'heading', the second question and answer gives a good overview.
For changing fonts, I've got a solution for that buried in this answer, and it's surrounded by sympathy for people only finding the "cumbersome, using dozens of packages" methods. XeTeX/XeLaTeX and ConTeXt may make this task easier, and may be worth investigating as well.