Comprehensive SPICE guide

As mentioned in another answer, the independent users group on Yahoo is an excellent community resource for questions about Spice in general and LTSpice specifically.

For reference information and base-line documentation, the built-in help actually contains a wealth of information, although it is not always easy to narrow down on the relevant section. I usually use the "index" tab to find stuff instead of the "contents" tab.

For example, the circuit element syntax that you linked to is all covered in the help under the "circuit elements" section. The "waveform arithmetic" page is definitely worth a read for understanding the built-in calculator functions which can be used both for defining arbitrary behavioral sources and writing evaluative .measure statements.

I frequently see even relatively obscure LTSpice questions posted here on Stack Exchange and in the user group that are answered somewhere in the built-in help. It's usually worth a check before you look elsewhere.