My Great-grandmother spent a good part of her life doing genealogy, but when I started my own genealogical research, years after her death, I could find almost no evidence of her activity. After years of research, I finally found that all of her files had been sitting for years in my Aunt's basement. After this discovery, I was finally able to obtain the files that contained literally thousands of names, documents, letters, diaries, histories and other items. I spent the next fifteen years entering all of the data into computer programs and scanning all of the documents.
See the Mary Ann Linton Morgan Documents at the Family History Library in Salt Lake City, Utah on CD-ROM. CD-ROM no. 2328 pt. 1 and CD-ROM no. 2328 pt. 2 viewable on the Fam Hist FamilySearch Desktop.
In this case, most of the files were saved more through accident than design. Have you ever wondered what will happen to all your genealogical research upon your own demise? In another example, while I was presenting recently in Vero Beach, Florida, one of the Indian River Genealogical Society members presented the President of the Society with a stack of genealogical papers for their library. It seems that one of the local genealogists had dedicated a great deal of his latter life to genealogical research, but he had no close relatives and upon his death the stack of research was on its way to the dumpster when it was rescued by this friend from the Society. Will your genealogical files end up in the dumpster?
We all have the tendency to think that our relatives were special and so there must be a library or museum or historical society that would like our records. It is quite common at the Mesa FamilySearch Library for someone to donate their dead relative's records to the Library for safekeeping. This may very well be the case, but the vast majority of the genealogical papers donated turn out to be nothing more than copies of copies of old Family Group Records of no value to the Library or anyone else. In addition, the Library, like most repositories, has very limited space to store boxes of old papers that are neither cataloged or organized.
So, the first rule of preserving your research should be to do it right. Make sure what you are doing is really valuable research that someone besides yourself would be interested in preserving. Make sure it is adequately organized in an accessible genealogical database program and that the members of your family, whether they are interested or not, understand where and how they are organized. One good way to begin that organization is to digitize all of the source records you have in your possession, photos, documents, certificates, everything. Then make this whole collection available online to your greater family, thus increasing the chance that someone will be interested in obtaining those original records from you when you die.
It is not a good idea to depend on wills and court probate to take care of things like private papers (i.e. genealogical research) when you die. Unless the collection has some sort of monetary value that will be assigned by the estate, the documents can be summarily thrown out by the administrator or executor of the will, even if there was something in the will disposing of the documents. In addition, let's suppose that doesn't happen and the documents are given to the devisee in the will. What if the recipient of the documents throws them in the nearest garbage can? What can anyone do about it? Absolutely nothing, especially if the documents are considered "personal effects without value." Wills and probate are all about titled property and money, not genealogical research.
Providing for the documents to be given to some library or other institution is almost as futile. That is, unless the person giving the documents has made extensive prior arrangements for their acceptance and use by the library. This may include giving the library sufficient funds to store and catalog the documents. Of course, all this changes if the person dying is famous or rich. The library might be more than happy to get the documents of a famous actor or politician. But most of us are not famous and no one really cares about what happens to our research or documents.
The best case scenario is to make sure that everything is transferred to someone who is interested before you get too old to take care of your affairs. No matter how difficult it is to part with the stuff, give it away before it is too late.
In addition, make sure that all the information goes onto an appropriate website online that will keep the information off into the future. FamilySearch Family Tree has all the characteristics of such a place to put the information and if the present difficulties with the data are sorted out, that would be my first choice, merely because I figure they will have the greatest chance of longevity.