A couple that are still on my browser;

http://lilypond.org/doc/v2.18/Documentation/notation/index

http://lilypond.org/doc/v2.18/Documentation/learning/tutorial

Mostly I put stuff like

Headers in Lilypond

anacrusis in Lilypond

Chords in Lilypond

into a search engine. (I don't use G**gle!)

I did this four or five times but I can't remember any more details.

Oh another one was

Tutorials in Lilypond.

These proved useful, as was the program Frescobaldi which, at the click of one button, displays the current score.