Popular themes for how-to guides include how to lose weight, how to quit smoking, how to get organized. But for those who want to start the new year on a different note, two guides aim at people resolving to have more fun or, at least, not go crazy.

“How to Think More about Sex”

By Alain de Botton ($5.63, Amazon.com)

“How to Think More about Sex” by Alain de Botton asserts that it’s not that people think about sex too much – it’s that we don’t think about it the right way. The book covers such topics as love, lust, fetishism, adultery, pornography and neuroses, and considers why people often feel “somehow a bit odd” about having sex or even talking about it.

De Botton writes that the book isn’t designed to “teach us how to have more intense or more frequent sex, but rather to suggest how … we might begin to feel a little less painfully strange.”

“How to Stay Sane”

By Philippa Perry ($16, Picador)

In “How to Stay Sane,” psychotherapist Philippa Perry emphasizes the importance of fostering mental health, which often takes a backseat to physical health in daily life. Much like a fitness regimen for the mind, the book plots out a strategy – with a variety of mindfulness exercises – to help “not lose your mind in the modern age.” Among them are ways to observe oneself more carefully, analyze relations to others and fill lives with “unusual” experiences.

Cold and flu

Exercise can be a good way to fight off illness, but don’t overdo it.

Fitness magazine

If you needed another reason to stay active, exercise is now receiving props for helping thwart illnesses.

According to Fitness magazine’s December issue, the right type, length and intensity of activity can help you fight the common cold or flu.

“Moderate exercise helps boost immunity by increasing the movement of immune cells,” said David Nieman, a professor of health and exercise science at Appalachian State University in Boone.

But not all sweat sessions are created equal. Long, intense workouts can leave you exhausted and compromise your immune system.

If you’re already sick? “Heavy exertion during an illness, particularly a fever or flu, can worsen and prolong your symptoms. … But a runny nose isn’t a free pass to lounge in bed.”

If you have a minor headache, minor cough, runny or stuffy nose, sneezing or a mildly sore throat, you’re good to go. But more severe symptoms such as migraine, chest congestion, wheezing, body aches and fever are prohibitive. And in any case, don’t push to the point of being exhausted.