Found in 2 comments on Hacker News
lpolovets · 2017-09-25 · Original thread
I've heard great things about Predictable Revenue ( and The Sales Acceleration Formula ( but haven't read either yet. I think they're focused more on selling products than services, but not 100% sure.
austenallred · 2015-09-17 · Original thread
"Sales" is very broad.

My favorite book about the act of selling (i.e. pitching) is "Pitch Anything" -

If you're looking for an overall sales primer/bible, your best bet is probably The Sales Acceleration Formula

Fresh book recommendations delivered straight to your inbox every Thursday.