One of the best resources for indexing your genealogy is Indexing Family Histories: Simple Steps for a Quality Product by Patricia Law Hatcher and John V. Wylie. Published by the National Genealogical Society in 1994, it is currently out of print but available at many libraries and genealogical societies. The following guidelines are just some of the many valuable pieces of information in the book.
Many factors go into producing a good index, not the least of which is the formatting. When publishing 6”x9” pages, it is best to have a two-column index. Three columns work well for an 8.5”x11” book. The type style should match the text and be one to two points smaller than the main part of the book.
A long list of subentries and page numbers separated by semi-colons written in paragraph style after the main entry is difficult to read and should be avoided. Each subentry should be indented about .25” under the main entry. Page numbers should appear immediately after the subentry, preceded by a comma. Do not right-align page numbers as this is also very difficult to read.
An introductory paragraph is an excellent way to communicate how the index works, what items were and were not indexed, and how multiple entries were combined or cross-referenced. This will make the index crystal-clear to the reader.