Helm might have info documentation, available offline within Emacs. Try `M-x info-apropos` and type "helm". Info docs form a tree: press '^' to go up a node,

Helm might have info documentation, available offline within Emacs. Try `M-x info-apropos` and type "helm". Info docs form a tree: press '^' to go up a node, 'n' and 'p' to go forward and back on same level, '[' and ']' to go forward/back a page like a book.