|Atlas of Lie Groups and Representations|
(also see tables of unipotent representations)
Tables of unipotent orbitsClasses Unipotentes et Sous-Groupes de Borel by Nicolas Spaltenstein has tables of unipotent conjugacy classes for the exceptional groups. These are reproduced in Roger Carter's book Finite Groups of Lie Type: Conjugacy Classes and Complex Characters. Unfortunately these books are out of print and hard to find. Some of this can be found in Nilpotent Orbits In Semisimple Lie Algebras by Collingwood and McGovern, and various papers.
Birne Binegar has an online database of unipotent orbits with all of this information, and much more.
Here are tables and pictures of unipotent orbits for the exceptional groups. These have most of the information of the tables from Spaltenstein and Carter, and some additional data. To get all the information in these files, download All Exceptional Groups in one text file (text file) and Enhanced closure diagrams for exceptional groups (pdf file).
Tables of unipotent orbits (text files)
Closure diagrams of unipotent orbits (postscript files)
Enhanced closure diagrams of unipotent orbits (postscript files)These pictures include extra information about the orbits. See the pdf file above for more information.
Enhanced closure diagrams for all exceptional groups in one pdf file