Whether you're the bookish sort that wants several large bookcases, or you want a simple wall shelf to display a couple goodies, there's a wide variety to choose from. Note that there are MANY naming inconsistencies between recipe names and item names, in the form of bookcase vs bookshelves, shelves vs. shelf, so don't be thrown when you find a recipe for "short maple shelves" makes "short maple shelf" and so on.

The Combine Bookshelf listed below is from the carpenter books awarded by a questline in the Withered Lands for level 90+. ("Rare" means that it is from the advanced books from that questline, and that it requires a rare primary ingredient.)

Alder Bookcase Tier 1 Rare Status: 40	Primitive Elm Bookshelf Tier 1 Status: 20	Bone Bookcase Tier 2 Rare Status: 60
Maple Bookcase Tier 2 Status: 25	Short Maple Shelf Tier 2 Status: 25	Gukta Maple Shelf Tier 2 Status: 25
Medium Maple Shelf Tier 2 Status: 25	Small Fir Bookcase Tier 3 Rare Status: 100	Tall Fir Bookcase Tier 3 Rare Status: 100
Small Fir Double Shelf Tier 3 Rare Status: 100	Standard Ash Bookcase Tier 3 Status: 30	Standard Ash Shelves Tier 3 Status: 30
a Short Militia Shelf Tier 3 Status: 30	Classy Double Oak Shelf Tier 4 Rare Status: 300	Ornate Oak Bookshelf Tier 4 Rare Status: 300
Briarwood Bookcase Tier 4 Status: 35	a Long Ornate Shelf Tier 4 Status: 35	Briarwood Shelf Tier 4 Status: 35
Cedar Militia Double Shelf Tier 5 Rare Status: 500	Tall Cedar Bookcase Tier 5 Rare Status: 500	Small Cedar Bookcase Tier 5 Rare Status: 500
Classy Cedar Double Shelf Tier 5 Rare Status: 500	Teak Bookcase Tier 5 Status: 55	Elaborate Teak Shelf* Tier 5 Status: 55
Fancy Teak Shelf* Tier 5 Status: 55	Ebony Warlock's Bookcase Tier 7 Rare Status: 900	Ebony Wizard's Bookcase Tier 7 Rare Status: 900
Large Mahogany Bookcase Tier 8 Rare Status: 1100	Ornate Mahogany Bookcase Tier 8 Rare Status: 1100	Small Mahogany Bookcase Tier 8 Rare Status: 1100
Mahogany Display Case Tier 8 Rare Status: 1100	Large Redwood Bookcase Tier 8 Status: 125	Weathered Long Library Bookcase Tier 9 Rare Status: 1300
Weathered Wide Library Bookcase Tier 9 Rare Status: 1300	Weathered Library Pillar Tier 9 Rare Status: 1300	Weathered Low Library Bookcase Tier 9 Rare Status: 1300
Weathered Tall Library Bookcase Tier 9 Rare Status: 1300	Dark Sumac Bookcase Tier 9 Status: 250	Sumac Bookcase Tier 9 Status: 250
Kromzek Bookcase Forgemaster Faction recipe Status: 175	Ornate Bookcase of the Shadowed Forgemaster Faction recipe Status: 175	Ornate Shadowed Stone Bookcase Forgemaster Faction recipe Status: 175
Shadowed Stone Bookcase Forgemaster Faction recipe Status: 175	Bookcase of the Shadowed Forgemaster Faction recipe Status: 175	Combine Bookshelf GU63 Rare

Another interesting little fact is that the two ebony bookcases, while they appear to be pre-filled with books, are able to have more books manually placed upon the shelves.