I've actually seen it listed as among Lovecraft's worst work, but I have to disagree. Yes, he wrote it strictly for a paycheck, and yes, he was making fun of Mary Shelley's FRANKENSTEIN the whole time, and he hated the "cliffhanger" format that was imposed on him by the magazine, but it's a story that proves Lovecraft could write comedy, which is worthwhile in and of itself.
The story details the major incidents in the life of Herbert West, from his time as a medical student at Miskatonic University, to holding a practice in nearby Bolton, to serving in the Canadian Army in WWI prior to American involvement in the Great War. West's interest is in finding a cure for death; to this end, he spends years experimenting with ways to reanimate dead tissue. He has a number of issues along the way, mostly dealing with the "freshness" of his test subjects -- if the brain cells aren't fresh enough, his subjects revive as violently insane, cannibalistic horrors. As he goes, West becomes more and more callous and hardened to the sources of his test subjects, sinking deeper and deeper into criminality in pursuit of his obsession. Of course, eventually the fruits of his obsession begin to pursue him...
I actually really like this story. I like how, with the cliffhanger structure imposed on Lovecraft, each chapter is it's own complete short story, capable of being read divorced from the others and still making perfect sense. Lovecraft also displays a wicked sense of dark humor here, one that calls to mind Ambrose Bierce's "The Damned Thing"'s chapter headings. For example, here's a passage from "Herbert West":
It is uncommon to fire all six shots of a revolver with great suddenness when one would probably be sufficient, but many things in the life of Herbert West were uncommon.
This is an excellent example of the humor of understatement, or as Lovecraft would undoubtedly prefer it, the humour of understatement. Given Lovecraft's well-documented Anglophilia and the fact that understatement forms the basis for British humor, I'm not surprised that Lovecraft would show a preference for this style of humor.