The first book can be purchased in OSRS gold the related NPCs for 100k, then after you started a first publication you need to finish it before working on another summoning book. Your first book is totally free. The webpages can be purchased in the related NPCs for 400k per webpage, which means its easier to receive it yourself. Each webpage is dropped by the associated monster.
What does every summon do? Goblins - Strike level is elevated by 1, so let's say you have 50 assault and summon a goblin, then it becomes 51/50. Hobgoblins - Power level is elevated by 1, in other words same situation as above except for strength. Ogres - Defence and strength is elevated by 2, assault is 5. Hill Giants - Strength is elevated by 1, Defence by 2, and attack is decreased by 2.
Mountain Troll - Strength, Ranged are raised by 1, Power is increased by 1, and attack is decreased by 3. Cyclops - Defence and Strength is raised by 7, assault is decreased by 13. Locust - Has a chance of blocking attacks against youpersonally, when attack is obstructed will cause 3 damage to the creature you're fighting. Scarabs - gets a chance of blocking attacks against you, as soon as an attack is blocked, they will circle your target preventing your target from attacking for three strikes.
Cave Bug - Acts as a lantern in dungeons. Jungle Spider - While summoned has a chance of incorporating a random poison strike to your weapon. Shadow Spider - While summoned your weapon has a possibility of draining prayer from your opponent equal to a damage, however the Shadow Spider also includes a chance of attacking you inducing up to 5 damage and stealing half your own prayer. Poison Scorpion - bettering your defence by 1, and buy RS gold has a chance of adding poison strike to your own weapon.