Custom Builder Business Plan Kit by National Association of Home Builders (NAHB Press, 1993; 800/368-5242). Three-ring binder, 101/2x111/2, 136 pages, $61.50 (discounted for members). Whether you're just starting up a construction business or you need capital to expand your current operation, you'll soon be meeting with a loan officer at your bank. One of the first questions he or she will ask is, "May I see your business plan?" Not, "Do you have one?" but "Where is it?" You'd better be able to produce one and also be familiar enough with the information in it to chat easily about things like balance sheets and profit-and-loss estimates. A business plan will help to convince the bank that your company