The Official Civilization Revolution Site has posted two handy reference PDF files for the game. The first is a tech tree (http://www.civilizationrevolution.com/community/pdfs/TechTree.pdf) containing all the arrows and what each tech allows and obsoletes, along with icons for each item. It's something I plan to do for the CivRev tech tree I made (http://www.civfanatics.com/gallery/showimage.php?i=1791&original=1), but now obviously it's not necessary anymore. :)

The second reference PDF (http://www.civilizationrevolution.com/community/pdfs/TechTreeDetails.pdf) contains 5 tables for units, wonders, buildings, government, and terrains.