Rewarded Skill Points

Act 1

• +1 - Quest: Kill Nessus. Greece.

Act 2

• +2 - Quest: "A Beast of Legend" - Wadjet Canyons.
• +2 - Skill points from obtaining the Eye and the Staff.

Act 4 (Immortal Throne)

• +2 - Quest: The Dust of a Titan, Far Plains North of Salt Flats

The "Reward Attribute Points" selection will allow you to add in these points to your build.

For more information on the quests, the TitanQuest.net forums has a great link outlining the quests and their locations.