When you are deciding what courses to take you should run your Academic Audit Report. You can also run an audit for a major that you are considering but haven't declared to see that major's requirements.
The academic audit has information about you: your name, declared major (you will be listed as a HOO if you are undeclared), department, school (DC), andrew ID, class level, cumulative QPA, units passed, units in progress, and units upcoming. You will see the name of the major you choose followed by the minimum units for graduation (360 for all DC majors).
The General Education (GenEd) program is listed by Categories. You can use the GenEd website to find the courses that fulfill the "unfilled units" list in the Academic Audit Report. When you are taking a course, it will list the course number, the semester it was taken, the grade (* when you are currently taking it), and the number of units. Courses that you have taken but are not needed for this particular audit will be listed separately; these courses count towards your unit total for graduation. If you have questions about your GenEd program courses, contact your AAC advisor.
The requirements for the major are listed below (or above) the GenEd requirements. If you have questions about completing courses for your major (and graduation), contact your Primary Major advisor.
Once all the requirements for the Gen Ed Program and your major(s) are complete and you have reached the 360 minimum units, you will be eligible to graduate!
For planning purposes (semester-by-semester), you might want to use a chart like this.