SuperCollider has a built-in help system. To see the main help page, press cmd-d (without first selecting anything). From that page, click on underlined topics. Another useful document is More on Getting Help.
In general, there are help files for classes (capitalized words, such as SinOsc, Array, Nil, etc.). Select the name of a class and press Cmd-d. A help file, if one exists, will open.
To see source code for class definitions, select the name of a class and type cmd-j
To see how a class or classes implement a particular message, select the message name and press cmd-y.
Use the Find and Find Next commands, available through the Edit menu, to search for text in the frontmost document
Use grep in the Terminal (in the Applications->Utilities folder) to search for all occurrences of a given word or phrase. For example, to see all documents that use the LFSaw class, evaluate (in the Terminal application)
Because lines in the terminal application break according to the size of the window and not through schemes that enhance readability, it may be easier to write grep results to a file, as in
The SuperCollider wiki:
The SuperCollider users mailing list archive:
The SuperCollider user or developer lists (or both).
David Cottle has a large course on sound synthesis based around SC3.
A course by Nick Collins:
The pseudonym tutorial:
The MAT tutorial (UC-Santa Barbara) tutorial:
go to 05_The_network