Finding information about people can be a difficult category for research. While the information found through free resources can often be said to be somewhat accurate, often the information is not current. Information found in commercial databases is usually more current. When looking for information on people, it's a good practice to check multiple resources to verify that what you found is both accurate and current. This is a process that requires patience.
NOTE: don't be fooled into thinking that just because you are paying for information that the information you receive will be accurate and current. Just like with other research databases, some people-finding sites are better than others; experiment to find one that works best for you.
"Although many [Facebook] groups are private and you might need an invitation or a source inside them to gain access, the world’s largest social network is a trove of publicly accessible information..." Learn more here: https://thegroundtruthproject.org/tools-tips-digging-facebook-two-investigative-journalists/
Free sites for finding home (or even business!) addresses can be hit or miss, depending on the availability of information. If you are using one of these "freemium" (i.e. free up until a certain point) services for service of process, you want to double-check your findings against any county property records to make sure that your information is current and accurate.
NOTE: this list is not exhaustive, nor does this guide claim that these resources will provide comprehensive information.
Identifying the owner of a phone number, top 5 sites: https://www.makeuseof.com/tag/top-8-online-tools-to-identify-the-owner-of-a-phone-number/
Outside of a FOIA request for documents from the appropriate government body, there might not be an easy, free way to procure someone's criminal record history. There sites are examples of places that might give you some insight as to what you might want to request from that government body.
This is one category in which you should use what you know to try to track down what you need. Certain legal proceedings require parties to disclose their assets, like Bankrupcy records and divorce records. For corporations, they might have to disclose the company's assets on their balance sheets.
You can also do some hunting on your own: look at a person's social media pictures to see if they show off what they own. A new car, that's an asset. Social media sites like Facebook, Twitter, Instagram, Flickr, and more allow you to browse through pictures.
Intellectual property might also be considered an asset. Please ask a librarian about searching for IP records.
Inquiring about the active duty military status of an individual constitutes a records request, but one that might be necessary prior to an entry of a default judgment. If the individual is actively serving, it could be why they are not responding to complaints or other attempts at communication.
Deeds and property titles have to be filed with the appropriate office in a given jurisdiction. In these jurisdictions, this office can be called the Tax Assessor, the County Recorder, County Index, or something along those lines. These offices also collect mortgage documents. Not all county offices have made their databases publicly available. Often, you might have to visit the municipal office and speak with the clerk about obtaining these records.
Property records can help you assess whether someone is a landowner, and can be used to verify the accuracy of addresses, and for determining the assessed value of a property.
Commercial real estate sites can assist you with determining the fair market value of a property.
This is another category to think about where you know information you need may already exist. For instance, if you're looking for death records, you can check newspapers' obituaries or even funeral home websites. Newspapers also publish marriage announcements. Depending on the year of birth, you might be able to use some of your knowledge of social media websites to find birth announcements. Other states' Department of Health website may also be able to shed light on where to find information outside of your jurisdiction.
Plan your litigation strategy. Get familiar with a judge's case load, their motion grant rate, or their appeal rate. You can also learn more about opposing counsel by researching their past case work, and they types of cases they've tried.
If a profession requires a practitioner to be licensed, you should be able to look up the status of that license online. Any given profession that requires a license will likely have an oversight body, like a Licensing Board, either on the state level or the federal level, or both. Visit the website of the Licensing Board to check on the status of a license.