High schools in California--and around the country--increasingly offer computer science (CS) and often would like to expand CS offerings further. However, these expansions pose a number of challenges for administrators and policymakers, especially if they are going to happen effectively and equitably. We consider four of the most pressing challenges for CS expansions: (a) staffing issues, including equitable access to CS teachers; (b) curricular capacity; (c) school accountability pressure; and (d) equitable access to CS coursework. For each challenge, we discuss what the research tells us about what is already happening as well as potential solutions going forward.