The bibliographic information: Generally, the bibliographic information of the source (the title, author, publisher, date, etc.) is written in either MLA or APA format. For more help with formatting, see the MLA handout. For APA, go here: APA handout.
The annotations: The annotations for each source are written in paragraph form. The lengths of the annotations can vary significantly from a couple of sentences to a couple of pages depending on how many entries you have. If you only have a few entries, then by all means use lengthy descriptions! If you have a hundred, then short descriptions are best. The length will always depend on the purpose. If you're just writing summaries of your sources, the annotations may not be very long. However, if you are writing an extensive analysis of each source, you'll need more space.
To help you out, here are some links to lists similar to the format types I consider gradable.
1) Traditional (printed) formatted list with annotation
- Perdue OWL: https://owl.english.purdue.edu/owl/resource/614/03/ These are examples of traditional formats including MLA, APA, & Chicago
- Cornell University: http://guides.library.cornell.edu/annotatedbibliography Some general guidelines with examples
2) Formatted wiki - fan created resource
- Star Wars Wiki http://starwars.wikia.com/wiki/Main_Page note how the information is organized on the wiki, with designations of cannon and non-cannon (extended universe). This is too detailed though, as it is not restrained to simply the story entries.
- Walking dead Wiki http://walkingdead.wikia.com/wiki/The_Walking_Dead_Wiki Note how this wiki has easy to access tabs for each of the major story formats via media form.
3) Formatted website - franchise/industry created resource
- Walking dead AMC website http://www.amctv.com/shows/the-walking-dead/episodes and http://blogs.amctv.com/the-walking-dead/# are most notable for their official episode guide and as a portal for embedded content itself via the official network pipeline.
- The Guardian's Walking Dead Episode Guide http://www.theguardian.com/tv-and-radio/series/the-walking-dead-episode-by-episode notable because of the short externally cited descriptions but with comments enabled to allow for audience interaction with the site and reaction to the episode all for content not created by them in any way.