One of Yale’s open courses has a lecture that covers The Crying of Lot 49[1]. A good place to start for anyone reading Pynchon for the first time.
Gravity’s Rainbow is my personal favourite, but takes an enormous amount of work as a reader. His far-reaching and darkly conspiratorial view of the world is punctuated by hilarious moments of slapstick comedy, which can help keep you motivated through the more difficult sections.
By comparison I found Underworld and Infinite Jest to be much more straightforward. I haven’t read any Ellmann, so I'll have to check her out.
"The Crying of Lot 49" is the only Pynchon novel I was able to complete (bailed on "Gravity's Rainbow" and "V").
I think it was an easy enough introduction to Pynchon for this lightweight so I can certainly recommend it as well. Paranoia and conspiracy are on parade mixed in with perhaps an international secret society? But I don't want to give anything away....
Even from reading the one book, you will start to see references to Pynchon in other nooks of popular culture (W.A.S.T.E., Radiohead's fan club, comes to mind).
Gravity’s Rainbow is my personal favourite, but takes an enormous amount of work as a reader. His far-reaching and darkly conspiratorial view of the world is punctuated by hilarious moments of slapstick comedy, which can help keep you motivated through the more difficult sections.
By comparison I found Underworld and Infinite Jest to be much more straightforward. I haven’t read any Ellmann, so I'll have to check her out.
1. https://oyc.yale.edu/english/engl-291/lecture-12