Almanac - An almanac contains brief factual information on a broad range of subjects and is usually published annually. Typical information would be statistics, historical events, weather, geographical facts, awards, people, astronomy, economic facts, etc. An almanac may contain brief information on just about anything and is a good place to begin almost any search. Almanacs often cite the resources used, which will lead you to other specific resources. Encyclopedia - An encyclopedia contains information about a broad range of topics or one special topic.
Entries are generally longer than in an almanac, directory, or dictionary.
General encyclopedias are multi-volume with an index volume to help locate information on topics that do not have a separate entry. Not all information in an encyclopedia has its own entry, but instead may be covered in another entry and accessed only by using the index. Special subject atlases are also available on history, astronomy, archaeology, the environment, etc. Bibliography - Bibliographies are lists of relevant resources for specific topics. These may be a list of references at the end of an article or a whole book.