For SuperCollider there's a book which is not out yet (I have read a draft and found it excellent, especially for beginners) but it should be out soon.

You can try to send an email to one of the authors: http://www.music.utah.edu/faculty/faculty_a-z/david_michael_...

He used to send a pdf of the draft version if you asked him, but since the printed book is due soon (by MIT press) I don't know if this is still true.

There's also 'The Theory and Technique of Electronic Music' by Miller Puckette (the author of Pure Data):

http://crca.ucsd.edu/~msp/techniques.htm

The examples are, obviously, in Pure Data. But it is an excellent book and all the concepts can be applied to any synthesis language/tool.

For Csound there's 'The Csound Book' by Richard Boulanger (MIT Press):

http://csounds.com/shop/csound-book

This is also excellent. Disclaimer: the author is a friend.