I came across this document, The Handyman’s Guide To Understanding Transistor Data Sheets at the NRAO gov’t site. It’s a downloadable .PDF file. This document is great for those wishing to design and build RF and audio amplifiers, but unfortunately it has only a small paragraph at the end on switching, which is what the DC to DC converters such as a Joule Thief do. But anyone who uses transistors in their projects should become acquainted with the terminology and specifications of the datasheets, so he/she can make an intelligent comparison of the different transistors.