How do I look up information about someone with their social security number for free?

Not for free, but if you look them up on Roots Web's SSDI and click "SS-5", the page will generate a form letter for you. If you send it and $27 to the SSA, 6 - 8 weeks later you get a copy of the person's SSN application. It will tell you the person's name, address and occupation at the time, birth date, birth place, and parents' names - maiden name for the mother.

$27 may be your friend's food budget for a week, or it may be what she spends on the dinner wine when she doesn't have guests. It is breakfast for three at Denny's, if you skip the orange juice and stiff the waiter. It is half of dinner for one in a four-star restaurant in my part of the country. Your friend will have to decide if it is worth it to her.

You might take another route; SSN > SSDI > death date, then look up the people's obituaries on microfilmed newspapers in the public library, using the death date as a guide. Obits, in my experience, come out 0 - 7 days after the death. Some are better than others.

the front page of www.rootsweb.com has one (of many) online tutorials on records to use for genealogy, and where to find them.

Since genealogy always involves working from the present back, you will quickly run out of items relating to ss #. The program started in the mid 1930s. Qualified persons can send for the original file, which will have some info.

By the time you get to 1930 and earlier, you'll get into the census files as a key source. 1930 is the LATEST year open for research, but goes back to 1790..with varying amounts of data. You also will use birth/death certs when available (those start in ABOUT 1900, depends on the state), cemetery records, wills/probate files, and more. Everything will depend on the person and the locality/time frame. It will change as you work back.

Friendly tip that I normally hand out.. the internet is only ONE source of info for family history. Much is below the surface offline. Most important...documentation in good records is a standard that you have to keep in mind. You will find online files which USUALLY have lineages in the 1800s. Think numerically..each generation back, you double the number of ancestors, and the odds to find distant relatives with info. The downside is that not everyone understands what is an original document/ source..and by copying online "research".. will not recognize quality information from bad.

Use of that number is very limited and is coming under serious scrutiny because of the ties to identity theft. You can use it to access federal pension records on deceased public employees and railroad retirees. But beyond that, there won't be much. Date of birth, date of marriage and ddate of death are the more important pieces of informtion.