Your credit cards are maxed out, you're holding off on buying a new car, and you can't even look at your 401(k) statement. It's a whole new financial world out there. Here's the new rule book you need to get through it.

OLD RULE: Invest the bulk of your assets in the stock market.

NEW RULE: Only opt for stocks if you have a cast-iron stomach. Instead, divide your money evenly among stocks, real estate, and fixed-income investments.

The old formula — subtract your age from 100, and invest that percentage of your money in stocks — turned out to be too aggressive, says David Bach, financial expert, founder of, and author of the upcoming Fight for Your Money. The youngest among us have a long time until retirement, but putting too much stock in the market is risky even for them. Equities should make up one-third of your investment portfolio; put another third in real estate, and the rest in something boring (but safe), like a CD, money market account, or bond.

OLD RULE: Max out your 401(k).

NEW RULE: Max out your 401(k).

This one hasn't changed, even though people seem to think it has. The most important way to accumulate wealth is to always pay yourself first through an automatic deduction. But now that 401(k) balances are going down, millions of people have stopped contributing, says Bach. "This is a stunning statistic and a huge mistake." Now's the time to contribute as much as you possibly can, since the investments are cheaper. "You always want to buy things when they're on sale," says Bach. "This is the opportunity of a lifetime to increase your 401(k)."

OLD RULE: Increase your credit score by canceling credit cards.

NEW RULE: Have unused credit at your disposal. Emphasis on unused.

Thirty percent of your credit score is determined by how much of your accessible credit you're using, says Bach. The average American has more than nine credit cards, which actually isn't a problem unless you're maxed out. "Two or three cards is ideal, but consolidating down to one card right now can actually lower your credit score," says Bach. To persuade people to lend you money, you need to demonstrate restraint. Do that by showing that you have acess to funds but you're not using them.

OLD RULE: Speculate in real estate.

NEW RULE: Buy now, if you can. But buy to live, not invest.

For people who don't need to worry about selling a house, there's never a better time to buy, says Bach. "Homes are on sale for 50 cents on the dollar, and you may even be able to negotiate lower than that," says Bach. "We haven't seen the market look like this since the late '80s and early '90s." It's tougher to get mortgage than it was two years ago, because you now have to document your income. Run as fast as you can from adjustable-rate loans. "You'll have to settle for less of a house [because fixed loans are at a higher rate], but you'll be in a safer place financially," he says.