I'm starting work on a summer project at my university soon, based in General Relativity. In particular, my project is focused on slicing of black holes. The problem, however, I've never taken a General Relativity course(I've taken Differential Geometry, though), and I'm having trouble finding something to read that gives a "gentle" introduction to black hole slicings.

If you can recommend anything at all that I should read to help my understanding, I would be truly grateful.