(FORTUNE Magazine) – DEAR ANNIE: Two partners and I recently started a business based on what we think is a great and potentially very profitable idea. We're fast approaching the stage where we'll be seeking outside financing from banks and private investors, and call me paranoid, but I'm nervous about revealing what we're doing to people we don't know. What's to stop prospective backers from turning us down and then appropriating our business idea themselves? Is there any way to make it theft-proof, or do we just take our chances? WORRYWART Dear W.: Sometimes a little paranoia is a good thing. Without delay, and before you sit down with any investors or lenders, you'd be wise to file what's called a provisional application for patent, which allows you to establish a "first filing date" in the event that someone else later claims to have thought of your idea before you did. It also gives you the right to stamp PATENT PENDING on your business plan. Provisional patent protection, available since 1995, is much simpler and cheaper to get than a full-blown patent, and you can find instructions on how to apply for it at the U.S. Patent and Trademark Office's Website (www.uspto.gov). Once you have that nailed down, you have up to 12 months in which to file for a real patent. Marc Brown, a partner in the law firm Oppenheimer Wolff & Donnelly (www.oppenheimer.com), specializes in advising Internet startups. Says he: "We strongly recommend to our clients that they apply for a full patent within a month or two, rather than waiting the whole year to do it." You see, he's a little paranoid too.

Incidentally, in case you're wondering about the feasibility of patenting an idea, as opposed to a more tangible invention, a little background: Historically, business ideas, methods, and processes weren't patentable in the same way that new products were. That began to change in the '80s, when the U.S. Patent Office made a few exceptions. Then, in 1998, the federal appeals court for patent challenges explicitly ruled that an idea--as long as it is "novel and unobvious," that is, not just a variation on an existing notion--can be protected, and the courts have since backed that up. The shift has been a boon to Internet startups in particular. Consider: In 1991 just six patents issued in the U.S. mentioned the word "Internet." Last year alone, nearly 3,000 did.

Kurt Andersen's novel Turn of the Century, about (among other things) the machinations of Silicon Alley folk, has a hilarious recurring motif wherein hotshot entrepreneurs agonize over whether to ask their spouses, significant others, and even casual, um, paramours to sign nondisclosure agreements. You probably don't need to go that far, but Marc Brown recommends that you do require NDAs, as they're called, from potential investors. It's easier to get people to agree not to blab about your idea if you already have a proven track record as an inventor, he notes. If you don't, you may need to entice them to sign by revealing, pre-NDA, "not what your business plan is, but what you expect it to do." Explain its wonderfulness convincingly, in other words, but without giving too much away--an exceedingly tricky task.

Ultimately, safeguarding your great idea "comes down to the issue of trust," he says. "I urge all my clients to deal only with trustworthy people." Ah. And how does one identify those? Replies Brown with a sigh: "I wish I knew."

DEAR ANNIE: I'm in my 20s, but I already know that my long-term goal is to become chief financial officer of a company. Do you know of any guidelines on what kind of training I need, and what kind of jobs I should aim for now, to put me on the right track? NUMBERS GUY Dear N.G.: For starters, go to www.cfo.com and click on RESOURCES for a fascinating survey called "What CEOs Want in a CFO." As you'd expect, financial acumen and integrity are high on the list--but the 500 CEOs who answered the poll consider certain soft skills like leadership and persuasiveness to be just as important, so work on developing those too. Now, readers, how about it? Any CFOs out there? What career path led you to your current job? What formal training did you get? Write and tell all.

HAVE A QUESTION OR COMMENT? e-mail: askannie@fortunemail.com MAIL: Ask Annie, FORTUNE, 1271 Avenue of the Americas, Room 1559, N.Y., N.Y. 10020. Please include an afterwork phone number.

ANNIE OFFERS ADDITIONAL SHARP ADVICE ON WORKPLACE AND CAREER ISSUES ONLINE. POINT YOUR WEB BROWSER TO www.askannie.com.