First of all, you need to know what newspapers covered the area in which you are looking. Remember that many counties did not have newspapers until later - the 1850s, 1860s or after. Before that, smaller towns advertised in regional newspapers. You must remember that every county had to place its legal ads somewhere, in order to follow regulations. No matter what, legal advertisements had to be published. The trick is finding the newspaper.
One way to find the newspapers is to go to the county's homepage at www.rootsweb.com or www.usgenweb.com. The newspapers used are often listed on the individual county web pages. Local history books usually provide a summation of newspapers used by a county. Cyndi's List has a special section devoted to newspapers. Many state archives have the historical newspapers for the state online.
What is the best way to use these early newspapers? Many of them are indexed. You may want to check in your local genealogical library or on Worldcat.org to find where the indexes are located. If you can find the item through an index, it will save you lots of time.
Most people look for weddings, births, and obituaries. It must be remembered that customs have changed over the years. A large wedding for a prominent family may be found on the front page or on the society page with great detail. Smaller weddings may be placed near the local community news; some may have several paragraphs of information, and some may list only the bride, groom, and preacher. In many cases, the weddings are mentioned in the local news columns. Once again, these mentions in the columns may be detailed or not. As a rule, birth announcements will be in the local columns.
Obituaries in older newspapers may yield a disappointing lack of information. Often the only name mentioned is the person who died. Usually the obituary will list how long the person was in the county and from where the person came. This is helpful in moving back to another area. You need to always check the local columns for news about a death. Obituaries usually mention relatives of the deceased.
It can't be stressed enough how important these early news columns may be to your research. All sorts of information found its way into local news columns. You may even find when your ancestor painted his or her house! You may find stories of grandparents visiting the family, naming another complete generation. You may also uncover various relationships and other locations to search, in the columns that are categorized today as "social" or "gossip" columns.
Another great source of early information are the classifieds and legals. Probate records will yield death dates and possible names of relatives. Often people advertised their property for sale. Early newspapers yield a wealth of description. Many people would put in the legals that they would or would not responsible for another's debts, providing you with valuable relationship information. Foreclosure ads reflect the prosperity or the despair of the times. Looking through the legals is hard, but it may yield some pertinent pieces of information. In my family, we found from the legals that my great-great-grandfather William McGinty had been married a second time. We had checked the newspapers around his date of death and found the probate papers. Until that time, we had no clue of a second marriage.
Early newspapers often published lists of people who had letters left in the post office. These lists may provide a clue of how your ancestor traveled to one place or another. All that is on these lists is the person's name, but at least you will know if you need to look in a particular area or not.
If you know that your ancestor was a member of an organization or a business or trade group, you may check these columns, as well. Although no genealogical information may be found, in the sense of family, you will get a broader picture of your ancestor's life and his or her commitment to a certain cause or belief.
Looking through old newspapers may prove to be tedious, but the yield often outweighs the effort. No matter what you find, you will gain a greater appreciation of the life that your ancestor lived.