(FORTUNE Small Business) – When David Novak first went to jail, he hardly thought of it as a shrewd, career-making move. "I've got nobody to blame but me," he says. "I was the idiot who did what I did." Novak's conviction for mail fraud earned him ten months and 19 days in federal prison—and led him to start his current burgeoning business. As CEO and one of two full-time employees at David Novak Consulting (the other is his wife, Erin), Novak dispenses advice to white-collar criminals who are getting ready to do time. Needless to say, "We've been busier than ever," says Novak, 42, who is based in Salt Lake City. "The government is prosecuting at a prodigious rate."

Back in 1996, Novak was running a four-year-old aviation firm he had founded near Seattle called Cavu Flying Club. The company, which offered flight lessons and aircraft rentals—and was a consultant for Microsoft on its flight-simulator products—employed about 30 people. Looking back, Novak says he got overextended. His scheme for meeting payroll came right out of a Quinn Martin production: He ditched a Piper Cherokee in a bay to collect $80,000 in insurance. Then, coincidentally, he decided that he "wanted to start over" in New Zealand.

A month later, after a friend tipped him off about the insurance investigation, he turned himself in and pleaded guilty to mail fraud. He soon began serving his year-and-a-day sentence (later shortened for good conduct) at Eglin Federal Prison Camp, a minimum-security facility near Pensacola, Fla. Take away the volleyball and tennis courts and it is still just "three hots and a cot," as actual inmates probably never say.

What do inmates really say and do (aside from pounding their dinner trays and clanging their tin cups)? That is what Novak's nervous clients pay him $165 an hour to find out. He has even published DownTime—a "what to expect when you're expecting" for the soon-to-be-incarcerated—which he sells for $39.95 (gross margin: 70%). Of course, upstanding FSB readers will have no need of Novak's services—although he says he did encounter "several prominent solo practitioners" and one impressive insurance entrepreneur while he was in the can. So just in case you have a friend who might need Novak's advice, we asked him some questions. (The most common query is one about the showers that we can't repeat, but here is his reply: "Inmates are not animals. In the federal system, you'll do fine if you don't whine or complain.")

As an inmate, will I be expected to scratch each day off on the wall?

"Every inmate I've ever met has a calendar. Every Sunday I crossed out a week because it was more gratifying to do seven at a time. Einstein has nothing on a federal inmate when it comes to looking at time in different ways."

Can I still run my business from jail?

"There is a 300-minute monthly limit on phone calls. How are you going to run a business on ten minutes a day?"

What rules of etiquette are most important to know?

"Never initiate communication with a guard, or you will automatically be considered a snitch. Touching another inmate's possessions is one of the worst things you can do."

When I tell people where I'm going, should I call it the Big House, the Slammer, or the Joint?

"Refer to it as prison. Everything outside is the 'free world.' "

How soon after meeting people should I tell them I have been in prison?

"It should be the first thing out of your mouth. The social stigma you encounter is a little bit like what used to surround people who got divorced."

Are you worried that Martha Stewart will compete with you?

"There are more needy people than I can serve, so I would welcome the competition. If you figure out how to franchise this, I'll be glad to give you a royalty."