Spend up to 30 minutes per day thinking extensively about just one subject as a way to exercise your brain, advises Gretchen Rubin. Other ways to stimulate your brain and work on your social skills include talking on certain days without complaining or boasting and keeping others talking about themselves without allowing them to become self-conscious about it.

You have to become better at what you do, or the market will choose others instead of you, writes Seth Godin. If your career or a certain skill is something you're interested in, "you can do the hard work to get good at it," Godin writes.

LinkedIn will soon allow job seekers to discreetly let employers know they're open to new job opportunities. The Open Candidates feature will only be visible to those who work at other companies and pay for LinkedIn's premium recruiter service.

California recently passed a law creating a retirement program for employees who don't have access to retirement plans through their jobs. California is one of eight states to have this type of program in place, and by one count, at least 30 others are weighing similar initiatives.

You should never directly ask a hiring manager what salary range is being offered or how long it will take to get a promotion, writes Jacquelyn Smith. You should also avoid asking about benefits or flexible scheduling or posing questions about the company that show you haven't done enough research.

The flight of a baseball is affected by temperature, humidity and elevation, and a changing climate could lead to more home runs at hotter, humid ballgames, researchers say. The news gets worse for pitchers: As air gets less dense, especially at altitude, pitches break less and become more inviting.