This guide only includes official bookmarks, there are a lot of handmade/unofficial bookmarks available.
This blog site has some very good details about Tolkien Bookmarks
Tolkien Society
Mexican Tolkien Society
Bodleian Library Tolkien Exhibition
US Silmarillion Promo
Houghton Mifflin Promo
Harper Collins Promo
50th Anniversary Promo
Mathom
Fall of Gondolin Book Double Sided Promo
Leaf by Niggle
Puppet Show Promo
TheOneRing.net Fan Art Promo
ALA Library Read Promo
Unknown Publisher
Lord of the Rings Movies
Fellowship of the Ring
Tasseled with charms
Fold Out
Ring Verse with fold out map
Frodo with fold out character guide
Double Sided Promo
5 bookmarks
top row is one side, bottom is the other side
Italian Double Sided Promo
13 bookmarks
1 side shown
Major Cineplex Thailand
backs
packaging envelope
Sociedade Do Anel
Two Towers
Tasseled with charms
Collectors Edition (different charms)
Collectors Edition (ring charms)
Collectors Edition (ring charms)
Double Sided Promo
5 bookmarks
top row is one side, bottom is the other side
UCI Double Sided Promo
Harper Collins Double Sided Promo
Folding
Italian Double Sided Promo
Unknown
Return of the King
Tasseled with charms
collectors Edition (with charms)
Double Sided Promo
5 bookmarks
top row is one side, bottom is the other side
Academy Winner Double Sided
Gollum/Aragorn
UGC Cinema Promo
Lenticular
counter stand (double sided)
Italian Double Sided Promo
Trilogy Promo Double Sided
Singapore Exhibition Double Sided
Hobbit Movies
Unexpected Journey
Magnetic
Magnetic Bookmark Set A
Magnetic Bookmark Set B
3D
Odeon Cinema Promo
MGM Television Promo
Desalination is Smaug
Magnetic
Battle of Five Armies
Magnetic
Novelty Pen and Bookmark
WETA
Leather
Leather
Metal with charm
Between the Pages of the Book is a Lovely Place to Be
Hobbit Feet
Fairyloot Magnetic Bookmarks
Aragorn and Arwen