The first and easily the most accessible of Joyce’s three novels, A Portrait of the Artist as a Young Man tells the story of the early life of Stephen Dedalus, a fictionalized version of Joyce who will later appear in Ulysses. Cut down from a gigantic experimental autobiography, the work took Joyce the best part of 15 years, so you may be surprised to find how readable it is, especially if you have previously attempted to read his other novels.
The entire text is available here at Project Gutenberg
Here is a downloadable audiobook at Librivox
And here is the book for sale on Amazon
And here’s an episode of In Our Time on the book, if you can only spare half an hour