  We consider N=1 SU(N_c) gauge theory with an adjoint matter field $\Phi$, N_f
flavors of fundamentals Q and antifundamentals \tQ, and tree-level
superpotential of the form $\tQ\Phi^l Q$. This superpotential is relevant or
marginal for $lN_f\leq 2N_c$. The theory has a Coulomb branch which is not
lifted by quantum corrections. We find the exact effective gauge coupling on
the Coulomb branch in terms of a family of hyperelliptic curves, thus providing
a generalization of known results about N=2 SUSY QCD to N=1 context. The
Coulomb branch has singular points at which mutually nonlocal dyons become
massless. These singularities presumably correspond to new N=1 superconformal
fixed points. We discuss them in some detail for N_c=2, N_f=1.
