Most genograms include basic information about number of marriages, number of children of each marriage, birth order, and deaths. Generally males are identified on a genogram with a square, females with a circle. Deaths are indicated by an X through that individual's marker. Spouses are connected with lines, separations and divorces indicated by slash lines running through the lines. Ages by numbers in the markers.
Circles can include and indicate members outside the nuclear family living together.
Cutoffs, alliances, enmeshments, and stressful relationships are indicated by the nature of lines connecting individuals. I should be able to tell where these hypotheses came from. While genograms can easily be done by hand, many people in this computer age like software for this. Those of you who have PCs might appreciate this bit of freeware, Genopro. I use a Mac so this referral is sight unseen.