I need a SPSS tutor

I've almost finished the project, but just need some help controlling for third variables. Doing basic analysis of a data set for a student group learning SPSS together. We have the same data set, and each of us try to do our own analyses of statistical significance of the difference in mean between a control group and an experimental group, controlling for age and a dichotomous variable (major depression episode). The exact meaning of each variable is not that important, but I'd like help with how to use "Compare Means and Proportions" and "General Linear Model".