It's been sitting on my shelf for a few years now. I take it out and read a couple of pages each time and then put it back. Keep thinking I should buy a guide to reading this book but never got around to it.
Even a short summary of the Wake can suffice to get you started. You're never going to understand it all, and that's okay, but even a brief chat with a Wake fan can give you the basic clues of its structure and the HCE/ALP Shem/Shaun dualities. I think it's a mistake to spend time with guidebooks than with the text itself if you want to read it for pleasure as opposed to writing a thesis on it. At least, postpone the guides until after your first trip once around.