George Campbell's Neophyte Shipmodeler's Jackstay and Wolfram zu Mondfelt's Historic Ship Models both are available online, through the All Model site that was mentioned earlier in this thread. I recommend starting with the Campbell book. It was written way back in the sixties, primarily as a guidebook for people working on Model Shipways solid-hull wood kits, so it doesn't say anything specifically about plastic kits. But it contains a mass of solid, basic information about how sailing ships worked, and how they evolved over the centuries. Anybody who learns everything in that little book will be well on the way to being knowledgeable about the subject.
The Mondfelt book is also excellent. I've mentioned before that I have only two reservations about it in this context. First - it's extremely broad in its coverage; anybody wanting answers about a specific ship's rigging is likely to get frustrated. Second - it's extremely European. Many of the references to tools, techniques, and materials will be a little confusing to Americans. Mondfeld's frequent, approving references to walnut as a ship modeling wood, for instance, refer (I think) to a European variety of walnut that's quite different from what one finds in American lumber yards.
The literature on ship modeling and the history of ships is vast nowadays, and Grymm is right: many of the good books are expensive. They appeal to a relatively small, specialized market, and tend to go out of print in a hurry. But there are bargains to be had too. Last week I went looking for my old copy of R.C. Anderson's The Rigging of Ships in the Days of the Spritsail Topmast. (That's the basic source of information for anybody contemplating rigging a seventeenth-century ship model - such as the Soleil Royal.) I couldn't find it; I suspect it had gotten lost in a move. Out of curiosity I looked it up on the Barnes and Noble "Used and Out of Print" web page. (Go to www.barnesandnoble.com , then click on the "Used and Out of Print" tab near the top of the home page.) Barnes and Noble operates a network of used book dealers all over the U.S. I found several copies of the Anderson book. Mint-condition copies of the first edition (published by the Marine Research Society of Salem, Mass., in 1927) sell for more than $200.00. But a dealer in Wyoming had a copy of the Dover Books paperback reprint from the 1990s, in like-new condition, for (drum roll please) $4.00. I ordered it via the web on a Wednesday night (the shipping charges cost more than the book), and it arrived the following Thursday. Similar bargains can be found at www.amazon.com and www.bookfinder.com . The latter has an international network, and seems to have somewhat higher prices than the others.
Youth, talent, hard work, and enthusiasm are no match for old age and treachery.