It would be really cool if players could write and publish their own books in TESO. I would like to see a return of bookshops in cities. Players could pay the shopkeeper or librarian per copy to stock a self-published book.

Publish price would depend on number of pages and book cover/binding for one copy. This price would be increased for a stocking fee to have the book displayed in a library or bookshop. Copies could be bought for a mark up from these places by other players [or perhaps not as we don't know what kind of inventory space players will have yet].

Players could choose for their book:
1) Category: History, Literature, Geography, Biography, Journal, etc. - facilitates players browsing/searching books when in the shop or library
2) Title
3) Pen name - original (one or two names)
4) (optional) Guild or Faction (if enough Faction points) as a supporting agency
5) Book cover
6) Personal ink mark (color and pattern) for the title page
Only player written books would carry the personal seal so player-made books would be obvious from canon titles.

There are many players that are lore-buffs for TES and they maintain excruciating detail on wikis and libraries. I realize this feature would likely create a lot of erroneous "fan-fiction" but lore-based content would also be produced to flesh out the world with player-driven ideas.

I think it would be very cool to have this feature but perhaps it poses too much risk of distortion to the lore. (Hence the need for personal seals to mark player-contributions.)

Guilds Note:
I think it would be awesome if Guildmasters could write their own Guild Handbooks and stock them not only in libraries or bookshops but taverns for prospecting players looking for another guild. [You can join multiple guilds in TESO!] Writing a Handbook could be facilitated by a series of menus with optional sections to help keep Guild Handbooks somewhat uniform in providing basic information, goals, purposes, and rules. The sections that come to mind are: purpose/mission, goals, requirements to join (i.e. gender, race, level, skills), rules, penalties, rewards, quests, motto, insignia, colors, history and origins including legends (for RP fun).

While many guilds maintain websites for further information, some of the guild community information that is not displayed within in-game guild menus could be in Handbooks that members could be given or purchase upon joining.