There are two important sites related to enrollment at Berkeley:

• http://schedule.berkeley.edu is the course catalog
• https://calcentral.berkeley.edu/academics lets you sign up for courses

You may also take a look at the department website:

• http://astro.berkeley.edu/courses/graduate/2017/FL

You have until the end of the third week of classes to set your course enrollment for the semester. It's helpful for the professors if you enroll sooner rather than later, however.

Unless you have made arrangements otherwise, you need to enroll in AY C207, 290A, and 375 (if you are GSIing). You should be enrolled in at least 12 units of classes. The usual way to achieve this is to take the aforementioned classes, one further “real” graduate class (218 or a 250) and a seminar or two. Note that the “Ethics” class is more like a seminar than a “real” graduate class; it's certainly not prelim-able. You can also increase the number of units for 375 to fulfill the 12 unit requirement. The seminar courses have no requirements beyond your attendance at the weekly meetings. If you're going to be doing research in the fall and would like to sign up for research credits, you can inquire with Dexter to get the CCN for your research adviser.