Here are links to resources that I have found helpful and educational for my stained glass projects. 

http://www.delphiglass.com/

http://www.warmglass.com/

http://www.spectrumglass.com/

​https://www.mshdesigns.com/

http://warnerstainedglass.com/

https://www.creativeparadiseglass.com/tutorials​

http://www.fusedglass.org/