One of the benefits of the Internet is the sheer volume of information. One of the downsides of this is that anyone can put the information out there. The challenge, then, is not only to find the site that has the information you want but also to ensure that the information you found is valid. There are plenty of ways to find personal information on people for free--you just have to know where to look for it.
Write down everything you know about the person--where they live, at least city and state, his approximate age, any known relatives, kids, or spouses and/or her employer. If you only know his name, city and state, don't be discouraged, you can still get information.
Go to whitepages.com. Type in the last name, first name, if you know it, city and state. Hit "Find." The site will return a list of all people in that area with that first and last name, and people with a name close to it. It includes a list of cities associated with the name and an approximate age. It also contains people in the household.
Type the whole, or just last name, into a search engine such as Google, Clusty or Yahoo. In the search results, look for family web pages, myspace or facebook pages, or photo sites such as Flickr.com. These provide a wealth of free information about anyone. Families record marriages, births and life events like retirements and anniversaries. Detailed information can easily be obtained.
Look at the results from Step 3 for press releases from businesses, bios of staff members, published papers and news articles. These can be a source of business information, deaths, accidents, achievements and can reveal where the person currently resides, if you don't know.
Enter "free (your state) online public records" into any search engine. From the list of websites, you should be able to identify sites that contain government records. Depending on how modernised the government agency is, you can conceivably look up court records, tax records, document filings and numerous other records, simply depending on the level of computerisation of your destination search.
Try to go to sites that end in .gov when searching public records. These are the most reliable. Genealogy records are also reliable, but search through the comments in the forums associated with them to determine if this is set information or something still being researched. Social networking sites like Facebook and MySpace have huge amounts of information and should never be overlooked in a search list.
Be careful of any information you get on the Internet. Always ensure that the source can be trusted before you act on any information you retrieve.