Books are a cheap source of designs and advice, and of some fascinating historical material.
See my reviews of some boat design books. For those in the UK, I should point out that the magazines Classic Boat and Watercraft sell books and may have titles that are not currently available through Amazon. I could not possibly list every relevant title that Amazon supplies, so you might wish to use their search feature on their home page . Elements of Yacht Design Norman L Skene Another slim volume - but it answers a host of questions left unanswered by Teale, including how to calculate the stresses on an stayed or unstayed spar, and what are the relative densities of a variety of ballast materials. My copy of Elements was another second-hand bookshop purchase, and is dated 1936.