Documentation look up
C-c C-d h looks up documentation in CLHS. But it works only on symbols, so there are two more bindings:
C-c C-d # for reader macros
C-c C-d ~ for format directives
Other bindings which may be useful:
C-c C-d d describes a symbol using DESCRIBE
C-c C-d f describes a function using DESCRIBE
narrow and widen in org-mode
Just discovered org-narrow-to-subtree.
org-narrow-to-subtree)
