If you don't understand all the rules regarding Social Security, you can get burned at a time of life when you have little room for financial mistakes.

There's plenty to know; here's where to start.

advertisement | advertise on newsday

Children may be eligible. Children of older parents who are collecting Social Security retirement benefits may be eligible for children's benefits if they meet certain criteria, such as being unmarried and under 18, or 19 and still in high school. "Apply for benefits -- a lot of people aren't aware they exist," says John Male, a certified financial planner with The Gassman Financial Group in Manhattan.

Tap Social Security thoughtfully. Many people don't know when it's best to start benefits, says Peter Harris, an accounting professor at New York Institute of Technology in Old Westbury. Take Social Security before full retirement age and there's a permanent decrease in payments; take it later and there's an increase. Couples can increase their benefits by coordinating when and how they file for Social Security, says Doug Zarookian, a New York branch manager at Charles Schwab.

Divorcees have rights. Both ex-spouses may be eligible to claim spouse benefits simultaneously based on their former spouse's work history. You must have been married at least 10 years and divorced at least two, says Christine Fahlund, a Social Security expert with T. Rowe Price in Baltimore.

Pay Uncle Sam. Social Security is taxable. Depending on your income, up to 85 percent of your benefits may be taxed, according to IRS rules.