For classical groups such as $GL_n(\mathbb{F})$$GL_n(F)$, $SL_n(\mathbb{F})$$SL_n(F)$ for $F = \mathbb{R}, \mathbb{C}$, $SU(n)$, $U(n)$ and $O(n)$, you may find the cohomology ring structure and its proof in M. Mimura and H. Toda, Topology of Lie groups I, translations of mathematical monographs, vol 91.