This morning, Liz Pulliam Weston dropped by to talk about her new book, "Easy Money." It's a gem, full of sensible advice. We asked her for the three most important takeaways for people in their 20's and 30's. Here they are:

1) This Is Not Rocket Science. Most of us didn't learn personal finance in high school, in college or at home. It's easy to be intimidated by money, given the number of choices we all have to make. But it isn't that hard to get it right, a notion that we at FiLife wholeheartedly endorse.

2) Take Advantage of Technology. Automate everything you can. Liz is a big fan of automatic debits, where the mortgage company or a utility pulls the full amount of a bill from your bank account each month.

Don't want to give the electric company access to your bank account? Charge the bill to a credit card automatically each month. This saves money (and hassle), since you don't need stamps and envelopes and such. Plus, it keeps you from forgetting to pay, which can hurt your credit score.

3) Set Your Own Credit Limits. Liz notes that financial institutions don't really do this anymore. Credit cards let you blow through the supposed "credit limits" and just hit you with a fee when you go over. Mortgage lenders basically had no rules the last few years. Student-loan lenders seem willing to let you borrow as much as you want.

So how do you keep student loans from becoming a second mortgage (at least in terms of the size of the monthly payment)? She thinks the total amount you borrow shouldn't be more than you'll make the first year out of school, with the goal being that your monthly loan payment not exceed 10% of your pre-tax monthly income.

There may be good reasons for exceeding this limit, but at least it gives you a benchmark for how much debt is reasonable.

-- Ron Lieber