Everton, George B., Sr. The Handy Book for Genealogist. Logan UT: Everton Publisher, Inc, 1981.
Eichholz, Alice. Redbook: American State, County & Town Sources. Provo, Utah: Ancestry, 2004.
These questions bring up a major research issue for genealogists; looking for records that could not and do not exist. I am not talking about missing or destroyed records, but records that logically and historically cannot exist in the time period being examined. My experience is that this is a common issue, especially with genealogists with a certain level of understanding of records.
Birth certificates from government agencies are a good example. The earliest birth certificates were created in England in 1853. According to the "UNICEF SOWC Report" (Childinfo.org) accessed 18 February 2012 as many as 75% of the children in some developing countries are not registered even today. Historically, children who died shortly after child birth or who lived in rural areas were unlikely to be registered at birth. In is not uncommon, even today, to find people living in the United States who do not have a birth certificate. The Arizona data base of Vital Records, has birth records from 1855, but from personal experience, I know that many records are simply not there. Arizona did not require birth records statewide until after 1900.
So where do you go for birth records? Try family bibles, newspapers, church records, family correspondence, photographs, census records, state census records, and so on and so forth.
So how do we solve this problem? First of all there is a dismal lack of understanding generally among genealogists about the scope of records available and where they might be found. For example, how many people do you know who have read either of these books:
Eakle, Arlene H., and Johni Cerny. The Source A Guidebook of American Genealogy. Salt Lake City, Utah: Ancestry Pub. Co, 1984.
Greenwood, Val D. The Researcher's Guide to American Genealogy. Baltimore, Md: Genealogical Pub. Co, 1990.
Neither of these books are very recent, but then records haven't changed that much in the past thirty years or so. Just because records are online doesn't mean they are any different than those available around the country fifty or more years ago. After all we are looking for dead people, not usually for people who are living around us right now.
From time to time I write about records that no one seems to know about, including the major libraries. In this regard, cemetery records are a good example. I once sat in a sexton's office of a cemetery outside of Philadelphia, Pennsylvania and asked for records about my family members buried just a short distance from where we sat. Every time I asked a question, the office worker would disappear into another room and come out with another piece of paper. I finally had, one by one, quite a stack of paper, but she refused to volunteer even one sheet. Knowing what I know about cemeteries now, I will have to go back and ask for more because I did not ask for the burial permits or any transportation documents. If you want an interesting experiment, search for burial permits on Ancestry.com. You will see what I saw when I did the search and then realize that it is very likely every municipal cemetery and many private cemeteries have a file of burial permits from the state, county or municipality. As I have mentioned previously in other posts, these documents can be extremely valuable. In case you don't have access to Ancestry.com, searching over 30,000 collections for burial permits, brings up one collection from Kansas.
So what is realistic? If you spent a small percentage of the time you spend looking for names and instead looked for types of records and where they might be located, you would come out way ahead of the game. You also need to focus on the historical context of the records and exactly when and where the type of record may be found. It does no use to plumb a dry well. You need to look for records that exist at the time your people lived. Another example, the Library of Congress has a database called the US Newspaper Directory, 1690 to the present. You can search for any time period in any state or county of the U.S. and find out which newspapers were printed and where copies might be found. Part of the trick is learning enough about the sources to find the master sources that tell you what can be found and where. Part of that comes with experience and part of it comes with the realization that there are more records than any one person could examine in a lifetime so you have to search smart. Think about what kinds of records might have contained the information you are looking for at the time your ancestor lived and then try to find where those records were kept and where they might be now. But it is always a good idea to first ask if the type of record existed at the time in question.