Clerics normally have access to every spell in the Divine spell list. However, most other Divine casters only learn so many spells as they levels up.
Wizard class feature specifically says:
A wizard can also add a spell to his book whenever he encounters one on a magic scroll or in another wizard’s spellbook. No matter what the spell’s source, the wizard must first decipher the magical writing (see Arcane Magical Writings). Next, he must spend 1 hour studying the spell. At the end of the hour, he must make a Spellcraft check (DC 15 + spell’s level). A wizard who has specialized in a school of spells gains a +2 bonus on the Spellcraft check if the new spell is from his specialty.
Is any other caster capable of learning a spell that is on his spell list from a scroll, similar to Wizards? Does it require you to be Arcane, or could a Divine caster do it? Is this a spellbook-only thing?