A writer needs to be armed with the tools of the trade and the most useful of those tools is knowledge. Acquire it and use it.
Bibilography - Useful books and other sources
Tools of the Trade: All about pens, pencils, notebooks and computers
Most of these are secondary and even tertiary sources, so you should independently cooborate the information. And, of course, since you have found this information on the web, even the primary sources should be independently verified since I could be making them up. I'm not, but you don't know that for sure.