  We study expectation values of matrix elements for boundary values of the
resolvent as well as the density of states for a random Schr\"odinger operator
with potential distributed according to a Poisson process. Asymptotic
expansions for these quantities in the limit of small disorder are derived.
Explicit estimates for the expansion coefficients are given and we show that
their infinite volume limits are in fact finite as the spectral parameter
approaches the spectrum of the free Laplacian.
