Looking for a "Tube Guide"

A few that I'd recommend would be "Tube Lore" by Ludwell Sibley...."Tube Substitution Handbook" by William Smith...RCA Recieving Tube Manual.."70 Years of Radio Tubes and Valves" by John Stokes You can buy these at www.tubesandmore.com

Yes: Go to Audioasylum.com and cruise through the "tube" and "set" forums. Once you get aquainted the site has a full search feature which will allow you to research specific types. Just keep in mind that these are opinions and not gospel.

At Http://www.TheTubeStore.com -- In addition to selling a very large selection of tubes, they have a information section on tubes and tube basics that has a lot of good information.