Logistic regression diagnostics

I used to know this, but....

I am beginning a major new project using bivariate logistic regression. I know the assumptions for OLS (and how you test for them) but not for logistic regression. For example I think that you do not assume (and therefore don't need to test for) homoskedasticity or multivariate normality in logistic regression unlike OLS. I believe you do assumed the logit is linearly related to the IV (but not how to test for that is this is the case).

Any suggestions for what I have to test for in the assumptions or how to do this for SAS (or SAS EG even better).