How many Warriors books will there be?

They haven't decided when they want to stop, yet.

Here are the list of the Warriors books.

The Original Warriors Series:

Into the Wild

Fire and Ice

Forest of Secrets

Rising Storm

A Dangerous Path

The Darkest Hour

The Second Series The New Prophecy:

Midnight

Moonrise

Dawn

Starlight

Twilight

Sunset

The Third Series The Power of Three:

The Sight

Dark River

Outcast

Eclipse

Long Shadows

Sunrise

The Fourth Series Omen Of the Stars:

The Fourth Apprentice

Fading Echos

Night Whispers

The Sign of the Moon

The Forgotten Warrior

Warriors Mangas:

Into the Woods (Tigerstar and Sasha Trilogy)

Escape form the Forest (Tigerstar and Sasha Trilogy)

Return to the Clans (Tigerstar and Sasha Trilogy)

The Lost Warrior (Graystripe Trilogy)

Warrior's Refuge (Graystripe Trilogy)

Warrior's Return (Graystripe Trilogy)

The Rise of Scourge (Scourge Single)

Ravenpaw's Path Shattered Peace (Ravenpaw trilogy)

Ravenpaw's Path A Clan in Need (Ravenpaw trilogy)

Ravenpaw's Path The Heart of a Warrior(Ravenpaw trilogy)

Super Editions:

Bluestar's Prophecy

Firestar's Quest

SkyClan's Destiny

Crookedstar's Promise (Name may change)

Field Guides:

Secrets of the Clans

Cats of the Clans

Code of the Clans

Battles of the Clans