The Theory Department plays an active role in graduate student education through the Princeton University Program in Plasma Physics, with 9 members of the department serving as part of the faculty. The program covers a broad set of plasma physics courses including both a core curriculum and some advanced courses. All Princeton plasma physics graduate students do a first year experimental project and a second year theory project, and many members of the theory department have supervised second year theory projects as well as being thesis advisors. Here is a list of Ph.D. thesis titles and advisors.
PPPL also hosts short and long term visitors and graduate students from universities across the US and around the world, and members of the Theory Department research staff have been active in advising and collaborating with these Ph.D. students. Some of the current longer-term visitors (this list is frequently changing) are listed at PPPL Theory Visitors.
PPPL sponsors the Summer Undergraduate Internship Program, and PPPL theorists regularly advise participating students.