The following are several survey articles about Parameterized Complexity.

“Fixed-Parameter Tractability and Completeness I: Basic Theory,” SIAM J. Computing 24 (1995), 873–921, with R. Downey. [pdf]

“Fixed-Parameter Tractability and Completeness II: Completeness for W[1],” Theoretical Computer Science A 141 (1995), 109–131, with R. Downey. [pdf]

“Fixed Parameter Tractability and Completeness IV: On Completeness for W[P] and PSPACE Analogs,” Annals of Pure and Applied Logic 73 (1995), 235–276, with K. Abrahamson and R. Downey. [pdf]