There are far too many literary and philosophical references to be listed here. Some of the key texts to be familiar with as you approach the book are Homer's the Odyssey and Shakespeare's Hamlet (you might check out our Shmoop guides on these two books to get basic familiarity). Much of the philosophy is early Christian philosophy – St. Augustine, Thomas Aquinas, and others. We've tried to help you out in the line-by-line summaries, but the main place to look is Don Gifford's annotations to Ulysses, which make an effort to track down every allusion in the book.
Again, there are too many historical references to be listed here. Though many of the references are to Irish history (in particular to the long-time struggle for Irish Home Rule), Joyce also draws on European and world history at World War II. If you go through our episode summaries, we try to help you with a number of the references, but after that the place to look is Don Gifford's annotations to Ulysses.
Joyce's book is also drenched in Dublin popular culture. It's full of bits of music that were popular at the time; it has references to sporting events going on around 1904. Beyond that, Ulysses has quite a bit of local gossip that it's sometimes hard to understand without looking at the annotations. As always, we've tried to help you out in our line-by-line summaries, but the first place to look is Don Gifford.