Original Spinoza content:
Tractatus Theologico-Politicus (Theologico-Political Treatise, or the TTP)
People who are unfamiliar with Spinoza should read the TTP first, and then move on to the Ethics. If they start reading the Ethics and find its “geometric form” impenetrable, then they should move on to some of the secondary literature. Balibar’s Spinoza and Politics is the best for this. It situates Spinoza’s works in their sociopolitical context in the United Provinces during his lifetime and provides a clear, readable analysis of key concepts such as the unity of metaphysics and politics, political anthropology, and Spinoza’s theory of the state and democracy. In contrast to Balibar’s more “Marxist” introduction to Spinoza, Deleuze’s “Spinoza: Practical Philosophy” situates Spinoza as a predecessor of Nietzsche and gives an accessible overview to the core ideas of his influential reading of Spinoza. But beware: Deleuze has an agenda!
Tractatus Politicus (Political Treatise)
Tractatus de Intellectus Emendatione (Treatise on the Emendation of the Intellect)
Principia philosophiae cartesianae (Principles of Cartesian Philosophy)
The Political Treatise, Treatise on the Emendation of the Intellect, and Principles of Cartesian Philosophy should be read after the TTP and Ethics, pretty much in whatever order that interests the reader. Their subjects should be pretty clear from their titles…
Core contemporary applications of Spinoza:
Etienne Balibar, Spinoza and Politics.
Gilles Deleuze, Spinoza: Practical Philosophy.
Antonio Negri, The Savage Anomaly.
Pierre Macherey, Hegel or Spinoza.
The first two are the most accessible, but all four are essential. Negri’s take on Spinoza is the most “savagely” radical communist one, but it is a very difficult text. Macherey’s book is a powerful response to Hegel’s influential misreading of Spinoza (a misreading I see repeated very often).
Overview of scholarship:
Duffy, Simon (2009), “Spinoza Today: The Current State of Spinoza Scholarship.” Intellectual History Review 19 (1): 111-132. https://doi.org/10.1080/17496970902722973
Wiep van Bunge (2012), Spinoza Past and Present: Essays on Spinoza, Spinozism, and Spinoza Scholarship.
(In addition to the Balibar and Negri books.)
Warren Montag, Bodies, Masses, Power: Spinoza and His Contemporaries.
Frederic Lordon, Willing Slaves Of Capital: Spinoza And Marx On Desire.
Ruddick, Susan (2010), “Politics of Affect: Spinoza in the work of Negri and Deleuze.” Theory, Culture, Society 27 (4): 21-45.
Kiarina Kordela (2007), $urplus: Spinoza, Lacan. Argues against the Deleuze/Israel/Negri/Hardt conception of Spinoza (the “Neo-Spinozists”) as well as Zizek’s lazy dismissal of Spinoza as the “philosopher of late capitalism.”
Jacques Lacan (1932), De la psychose paranoïaque dans ses rapports avec la personnalité (Paranoid psychosis and its relationship to personality). This was Lacan’s doctoral thesis, very early work.
Theun de Vries, Spinoza in Selbstzeugnissen und Bilddokumenten. (Hamburg: Rowohlt Taschenbuch, 1970). Only available in German.
Steven Nadler, Spinoza: A Life. (Cambridge University Press, 2001).
Jonathan Israel, Radical Enlightenment: Philosophy and the Making of Modernity 1650-1750.
Other assorted suggested reading:
Gilles Deleuze, Expressionism in Philosophy: Spinoza.
My “to read” list:
Jon Miller, Spinoza and the Stoics. 2015.
Gregor Moder, Hegel and Spinoza: Substance and Negativity. 2017.