Ebook: Formal Semantics: The Essential Readings (Linguistics: The Essential Readings)

This is a great book if you are part of a younger generation that did not grow up professionally while these papers were first being written/discussed. A few selections seem out of place, or perhaps are not quite as foundational as others, but overall it is a collection well worth having. Read from beginning to end you will have a basic handle on a large number of central topics in semantics.

As a primer I recommend "Introduction to Montague Semantics" by Dowty, Wall, and Peters. Most papers within "... The Essential Readings" take for granted an understanding of PTQ theory that is historically hard to acquire just based off Montegue's original paper (which is included as Chapter 1 of "... The Essential Readings").