My suggestion would be to brew a couple of more kits, paying close attention to OG/FG readings. With the one gallon kits and a recipe calculator, the estimated values (from the software) and the actual values should match closely (within .002 or so) -- assuming your water levels are at one gallon. Review the recent threads here on refractometers. Do a forum search on "forced fermentation test".
While you're doing that, put together the chocolate coffee oatmeal stout recipe you wanted to try - it's a fun experiment.
For learning more about recipes, @uberculture, @loopie_beer, and @voodoo_donut each had an initial reply that is excellent.
I'll offer Randy Mosher's book Mastering Homebrew as a follow-on book to Brewing Classic Styles. Chris Colby's new book "Home Brew Recipe Bible" is also an interesting option to Brewing Classic Styles.