If you want to look at some theoretical stuff, find some definitions, or just new ideas: a list of online, organized EM sources.

CCRMA: Julius Orion Smith. Includes 4 courses. See also the JOS Global Index, a BIG glossary with definitions for many many technical terms & ideas.
See also: Planet CCRMA at Home, a monster collection of Linux audio software (runs under Fedora or CentOS.)

(More later … just a start for now)