Hi Mike,
A good simple book to get started in ship modelling, or getting the basics of building a toy boat, is "Ship Modelling, From Stem to Stern" by Milton Roth. $18.95 from The Dromedary Ship Modellers Center, 6324 Belton, El Paso, Texas, USA 79912 or phone Lois at 915 584 2445, she runs the place. Milton was her husband and founder/owner/operator of the Dromedary till his death a few years ago, he was also an avid modeller. Good folks. They sell: books, plans, kits, fittings and tools for ship modellers. Some of their kits are sailable. Don't know of any books specifically on "toy" boats though, but you should be able to whip one up easy enough aided by the fittings they supply. Pointy end goes forward....blunt end is aft, big stick in the middle sticking up is a mast and the flappy cloth on it, is either a sail or a diaper! I forget which!

Hope this helps.
Bob