NEW YORK (CNNMoney.com) -- President Bush signed The Unemployment Extension Act of 2008 into law Friday, lengthening the period of government assistance to Americans struggling in the shrinking job market.

The measure helps people whose benefits have recently expired, extending benefits by seven weeks in all states, and extending them for another 13 weeks on top of that in states with unemployment rates that have averaged 6% or higher over the most recent three months.(See state unemployment rates.)

So those who live in a high unemployment states will receive a total of 20 more weeks and nearly half of the states fit that criteria as of October, according to the Bureau of Labor Statistics.

Workers typically get 26 weeks of unemployment benefits, and it's not uncommon for the government to extend that during economic slowdowns.

Worried about how to make ends meet without a paycheck? Here's what you should know to take advantage of the new law.

How you qualify: To be eligible, you must be unemployed through no fault of your own and be actively seeking work. Requirements vary from state to state. Generally, wages earned and time on the job determine if you qualify and the level of assistance you will receive.

For example, In Washington you need to have 680 hours of employment in your base year - which is the first 12 of the last 18 months of work. In Nevada, a person must have earned at least $400 in one quarter of the base year to get help.

What you get: States have their own formulas for determining how much you will receive and for how long, but a general rule of thumb is that you will get half of your last paycheck for 26 weeks, explained Andy Stettner, deputy director of the National Employment Law Project.

In most states that is based on what you earned over your base year - up to a certain amount. Every state sets its own maximum, based on that state's average income. The average unemployment insurance benefit is $292 a week according to the Department of Labor.

When you get it: Experts recommend filing for unemployment on your first day out of work. It generally takes two or three weeks after you file a claim to receive your first check. In most cases there is then a "waiting week," and then you will receive your first unemployment insurance check the week after that.

What impacts your benefits: If you work part-time or freelance while you are collecting unemployment that will most likely reduce or eliminate your benefits. The same is true for severance checks in some states. You could still get a partial unemployment check but the formula for determining what percentage of your benefit you could still receive differs by state.

How to get in on the extension: In most states your unemployment insurance will be automatically extended if the Unemployment Compensation Extension Act passes. But to be sure, Stettner recommends calling your unemployment office to ask what you need to do to qualify.

To find out more about unemployment insurance benefits on a state-by-state basis, go to the State Unemployment Insurance agency.