Portrait is certainly more accessible than Ulysses or Finnegans Wake, but it lacks the delightful wordplay and zany, ambitious flights that leave the reader in wonderment. It has its obscure parts (of course, it's Joyce), but for the most part chronicles Stephen Dedalus's life from young childhood through college, recording everything that influenced him.
Some of these influences were recorded in more meticulous detail than makes for entertainment. For instance, the long, long passage giving the priest's sermon on sin and Hell was a flawless rendition of a classic fire and brimstone harangue. To describe it is to describe the problem with it.
I thought I had read this in college, but listening to the audio version made me wonder. If I did read it, I deserved a very bad grade for comprehension and retention.