There are 2 different types of manuals in game. One set teaches you a new skill and can be bought from the shops in game the other teaches you a new magic spell, these drop from monsters. To use the scroll double click.

Note: If you do not meet the requirments for the magic scrolls the scroll will disappear.

Shop Bought
		Recall Scroll Returning to the city, disappearance if used in a city
		Invisibility Scroll Invisible for 1 minute using with no weapon held in hands except staff
		Detect-Invi Scroll Detecting a invisible character
Siege Summons (Siege Information)
		Summon Scroll Used during a Siege to summon forth a soldier for your town. Including: Sorceress, A.T Knight, Elf Master, D.S Knight, Heavy Battle Tank and Barbarian
Obtained during a Siege with charm points. Can only be used during Siege. To use, double click.
Special Magic Scrolls
		Ice Storm Manual Requires 59 INT. Takes up 1x1 space, with an area effect of 3x3. Does high damage and freezes all targets. Stackable damage per Ice Storm
		Mass-Fire-Strike Manual Requires 85 INT. Teaches the user how to cast massive fire balls
		Bloody-Shock-Wave Manual Requires 105 INT. Teaches the user how to cast a chain of fire bolts
		Cancellation Manual Requires 135 INT. Teaches the user how to cancel all spells on the character including Protection from Arrow, Magic, Absolute Protection from Magic, Berserk and Defence spells
		Inhibit-Casting Manual Requires 172 INT. Teachers the user how to provent the target from casting spells for a short period of time.
		Earth Shock Wave Manual Requires 200 INT. Teaches the user how to call forth the power of the earth and summon a shock wave that goes from the character to the desired target. Drains stamina and damages armor as well as doing high damage.
Magic manuals dropped from monsters. To use, double click.
More information on magic can be found here