Usagi's good in that you can jump in anywhere, and you'll be right up to speed. (Unless it's like the middle of Grasscutter or something, but even then, Stan's very good at explaining what's gone before in an entertaining manner.) I've never read the Fantagraphics issues, and I had no trouble starting with the DH series. (I do have the FG box set pre-ordered.)
Does Dark Horse usually try to keep the BPRD HCs in print? Or have they just moved to the softcovers?
I've just ordered Hellboy Library Ed vol.1
"Freedom is the right of all sentient beings" - Optimus Prime