Most of the MAGMA routines are self-documented, which you can read in the files section of the doxygen documentation at http://icl.cs.utk.edu/magma/docs/
or in the source code itself.
We don't yet have an updated manual.
As for eigenvalues, there are syevd and heevd routines for the symmetric/Hermitian cases. Also sygvd and hegvd routines for the generalized symmetric/Hermitian cases.
The news release at http://icl.cs.utk.edu/magma/news/news.html?id=278
lists all of MAGMA's capabilities and the corresponding functions.