• Michel Brion: Invariants et covariants des groupes algebriques reductifs.
• William Crawley-Boevey: Lectures on representation theory and invariant theory.
• Kraft, H. , Procesi, C.: Classical Invariant Theory, a Primer.

Representations of Quivers

• Jon Brundan: Topics in Representation Theory.
• William Crawley-Boevey: Geometry of representations of algebras; Lectures on representations of quivers; Representations of quivers, preprojective algebras and deformations of quotient singularities.
• Harm Derksen: Quiver representations.
• Lieven Le Bruyn: Noncommutative Geometry @n.
• Charles Walter: Variation of Quotients and Etale Slices in Geometric Invariant Theory.