I recently had the opportunity through a client research project to delve into the world of records and histories created by the Methodist Episcopal Church, one of the predecessor denominations of today's United Methodist Church in the United States. For this particular individual, the research resulted in little snippets of information here and there, as he appears to have served as what is known as a "local preacher," rather than an ordained minister. He and his family were in Pennsylvania in 1850, in Ohio by 1860, and in Kentucky by 1870, which led me on a trail through the records of three different conferences. He appeared on occasion in Conference minutes associating him with various small congregations. Even better, he also could be tracked year-by-year through the three states where he lived and served via the marriages he performed. Court records document his posting bond to serve as a local Justice of the Peace as he moved into each new community, and county marriage records chronicle the marriages he performed in each location, sometimes identified as a J.P., and other times as a M.E. minister.
One thing I really enjoyed learning with this project was just how many early Methodist sources are available online. This won't be applicable to all Methodist research, of course. Many, many records are not yet available online -- found, instead, in conference archives, churches, and other locations. However, the wealth of information that can be found online pleasantly surprised me. J. Mark Lowe, who specializes among other things in Methodist research, introduced me to a digitized book that includes a list of all ministers ordained in the Methodist Episcopal church across the United States through 1839. This list appears in A History of the Methodist Episcopal Church, Volume 4: From the Year 1829 to the Year 1840, by Nathan Bangs, D.D., immediately following page 462, and can be viewed and/or downloaded online from Hathi Digital Trust, with digital copies also available through Internet Archive and Google Play. For example, Caleb Foster, a minister from western Pennsylvania, is listed as having been "received into full connection in the Methodist Episcopal Church" in 1836. Use your favorite search engine, and you may be able to find conference-created lists of preachers as well, such as Pastoral Records, published and updated by the Western Pennsylvania Conference of the United Methodist Church, which covers Methodist ministers from 1784 to 2010. For Caleb Foster, it provides his dates of birth and death, as well as information on his various church appointments and conference transfers.
Sites with large collections of digitized books can also be a good source for locating older editions of Methodist Conference minutes, journals and yearbooks. The Minutes of the Fifty-Ninth Session of the Rock River Annual Conference of the Methodist Episcopal Church Held in South Park Avenue Church, Chicago, Illinois October 5-11, 1898, for example, includes the previously mentioned memoir for Caleb Foster covering two full pages with information on his early years, his religious training, the churches and circuits in which he served, and his wife and family (Scroll through the book for the 1898 Conference as this digitized publication includes the minutes of annual conferences 1896-1900).
Now Caleb Foster was a well-known Methodist Episcopal minister, so he's mentioned in dozens of online Methodist sources. However, the same general research sources and strategies can be used to research lay ministers as well. If nothing else, online research may be able to help you narrow down the conference in which your Methodist ancestor served, so you can contact them regarding available records. See How to Research Methodist Ancestors for additional research suggestions and links.