I started using Lily for serious maybe a month ago, so I'm what you'd call new. I find the guide far more useful than the manual (the former seems more structured around how to do specific things, while the latter seems much more a general conceptual introduction).
However (and this is something I mentioned on a couple recent message exchanges), I feel that neither one of them gets me very far past making a single monolithic file using defaults. There's been a lot of mention (I imagine rightfully) about how Lily is capable, above all, of making beautifully engraved scores, and her suitability to managing a text-based, distributed, and version/change-tracked workflow. All of that sounds awesome, but I don't see anywhere where that's comprehensively documented.
Let's take my case: I'm transcribing masses from some obscure composer from the 18th century. There are no extant scores, only the parts (which ironically works better for Lily's structure). I want these scores to look their absolute best, and the underlying files to follow the best practices for structure and organization. I want to put the score and parts alongside the work of a commercial (read: Sibelius-using) house and have it be unambiguously a better-looking and standards-conforming result, and be able to show the incredible flexibility and rigorous flow-control that using the underlying system can offer.
I don't see anywhere in the reference or the manual where that sort of comprehensive style guide is presented. I'm thinking something like the doorstops O'Reilly's uses for documenting, say, HTML. I hate to use the term (it's already been ruined by bureaucrats), but what I'm really looking for is a comprehensive "best practices" style guide for how to organize larger scores.
Urs, I think this would probably dovetail nicely with your efforts to build a pool of competent engravers, as we would then all be working from the same style guidelines.
But that's just my use-case. Maybe there are others?
Cheers,
A