The cost of living is so high these days that even though many kids have good jobs, their pay may not be commensurate with what they have to pay out just to live.

There are a lot of young adults out there who have just lost their way. Some move home after a divorce, others just aren't making enough after college to afford a place of their own.

Some people would suggest you charge them 20 percent or even 30 percent, but you can still give your kids a break and teach them a lesson. Mostly you just want to use the rent as an incentive to encourage them to think about moving out as soon as possible. Otherwise they might get too comfortable and that isn't going to teach them responsibility.

How much you charge them will differ depending on the child and their circumstances. You should sit down with them and look at their cash flow.

I like individuals to use a home equity line of credit as opposed to a home equity loan, or second mortgage. The advantage of an equity line of credit is that you don't pay interest on anything other than what you use. You could have a $20,000 line of credit, but if you only borrowed $5,000 you'll only owe interest on that.

Some parents really have trouble having their kids know their business. The parents of Baby Boomers, in particular, came through a generation where the father of the house usually did all the finances and the wife or mother may not even know everything, so it's hard to develop that line of communication.

If you're getting too large a refund back that means you've not done a good job of anticipating what your taxes are going to be and you've given the IRS an interest-free loan all year. You have to adjust your withholdings this year to have your taxes break a little closer to even next year.