The Inheritance Cycle

Eragon
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rating: 3.75/5

Summary: A farm boy named Eragon finds a stone and thinks it might buy his family some food for the winter. But when the egg brings a baby dragon, he realizes that he has become a Rider, a protector of his country, and an enemy of the Empire that took over most of his country, including his city, Carhavall.

Eldest
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rating: 4/5

summary: Eragon needs to save the land from evil Galbatorix, the ruler of the Empire, but must first train with the elves.

Brisingr
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rating: 4.1/5

Summary: Eragon tries to save the people of Alageasia from Galbatorix, but that must wait another book.

Inheritance
website
wikipedia 
ARBookfinder
rating:4/5

(the book is also available as a paperback, like you saw the other three)
summary: Eragon wonders about "the vault of souls" a wercat told him about in book one. meanwhile, the varden's (varden is the name of the rebellion against evil Galbatorix) army is getting closer and closer to Uru'baen (the capital of the empire) and must begin the final battle soon. Will this "vault of souls" contain valuable information or objects, or is Eragon ready to confront Galbatorix?