Some links of interest:

The business I do audio work for--The Guitarist's Choice

Ampage--the best electronic musical instrument BBS on the net

Steve Bench's home page, an incredibly rich resource for electronics

Eduardo de Lima's articles on tube amps

Here's how to get a hold of some nice software off the web! Type in the name of a program, and click SEARCH.  Note that I have no connection to these websites other than these search links.