I see a lot of people coming on the ESO forum asking about what games they should play and what books they should read to get a background in TES lore. I thought it might be useful to some people to compile all the new lore added by the Elder Scrolls Online so far along with a brief summary of the background lore they might need for the Elder Scrolls Online. I will start with the ESO specific stuff and then move on to the background information.

For those with little to no knowledge of background lore, it might be useful to start with the later sections and then come back to the ESO specific stuff. It will be easier to understand with a base level of knowledge.

Your best source for lore is usually the games, but the http://uesp.net/wiki/Main_Page and the http://www.imperial-library.info/ are great online resources. UESP has all of the in-game books. The Imperial Library has all of the in-game books plus interviews with developers explaining those books and additional texts written by former/current developers that do not appear in game.

I plan on keeping this updated as new lore comes out.

NOTE: This post is designed to help people get ready for the Elder Scrolls Online lore in particular. For general TES lore see http://www.gamesas.com/topic/1112211-how-to-become-a-lore-buff/ and the http://www.gamesas.com/topic/15282-elder-scrolls-lore-faq/.

Elder Scrolls Online Lore, so far

This https://www.facebook.com/notes/the-elder-scrolls-online/introduction-to-the-lore-of-the-elder-scrolls-online-en/486381251371913 serves as a general introduction to the lore of the Elder Scrolls Online. There is also the http://elderscrollsonline.com/en/game-guide/story on the main website, but I personally prefer the Facebook post.

Each of the three leaders also has their own short book already: http://elderscrollsonline.com/en/news/post/2012/12/18/the-stories-of-tamriel-ayrenn--the-unforeseen-queen, http://elderscrollsonline.com/en/news/post/2012/12/03/the-stories-of-tamriel-jorunn-the-skald-king, and http://elderscrollsonline.com/en/news/post/2013/02/11/the-stories-of-tamriel-travails-and-triumphs-of-a-monarch by and about King Emeric.

http://www.youtube.com/watch?v=EDHa-77cy3I focuses specifically, not surprisingly, on the Alliance War.

Also, there are some great video interviews that focus specifically on the lore: one by http://www.youtube.com/watch?v=8_cKUX8H8JM and another by a representative of the http://www.youtube.com/watch?v=2Njunky0lhk&feature=youtu.be.

We have a few side texts as well:

http://www.gamesas.com/topic/1455331-the-worthy-ar-azal-his-deeds/ tells the story of a Hammerfell prince struggling with a politicized decisions to choose the bride. His ultimate decision is interesting to say the least.

http://www.gamesas.com/topic/1459910-cheeses-of-tamriel/ is something of a summary cook book. I like it because it gives you a http://www.youtube.com/watch?v=oShTJ90fC34 of the various cultures through a valuable but not immediately obvious lens.

Basic World Information

The best in-game lore summaries are the two Pocket Guides to the Empire. Here's the http://uesp.net/wiki/Lore:Pocket_Guide_to_the_Empire,_1st_Edition and here's the http://uesp.net/wiki/Lore:Pocket_Guide_to_the_Empire,_3rd_Edition. The Second is missing for reasons there's no need to get into now.

You should also read the summary articles about all of the races and their provinces on UESP. For example, about the http://uesp.net/wiki/Lore:Redguard and their home http://uesp.net/wiki/Lore:Hammerfell. The articles on UESP will have primary sources listed at the bottom of each page for further reading.

Religion

There are really two main texts you need to understand religion in Tamriel. There are tons of others but the man two are:

http://uesp.net/wiki/Lore:The_Monomyth

and

http://uesp.net/wiki/Lore:Varieties_of_Faith...

I would also read through the UESP summaries on each of the http://uesp.net/wiki/Lore:Aedra and http://uesp.net/wiki/Lore:Daedra.

Metaphysics

Our knowledge of metaphysics in the Elder Scrolls universe comes almost entirely from the http://uesp.net/wiki/Lore:The_36_Lessons_of_Vivec That one book outlines pretty much everything. However, its a long and very VERY complex read.

Luckily, Michael Kirkbride (the former developer and then writer for TES: Redguard, TES: Morrowind, TES: Oblivion, and the Oblivion expansion the Knights of the Nine) has since explained and summarized most of the teachings. http://www.imperial-library.info/content/cosmology and http://www.imperial-library.info/content/vehks-teaching will give you most of what you need to know from the Lessons in a much more easily digestible form.

History

Probably the best place to get a summary of the history of Nirn and Tamriel is the http://uesp.net/wiki/Lore:Merethic_Era. That link will take you to the Timeline for the Merethic Era, which is the first true era of linear time (the Dawn Era is the creation Era and stuff is pretty jumbled.) You can read up on the First Era and the Second Era prior to ESO as well.

In my opinion, the two most important things to read about for everyone to understand the context of the Elder Scrolls Online story would be the http://uesp.net/wiki/Lore:Alessia and the http://uesp.net/wiki/Lore:Reman_Dynasty.