If this breaks the rule please delete my comment but as an Egyptian I just wanted to clarify a couple of things. Egypt and Syria united under Nasser who was not a baathist but shared some of their views being both broadly Arab nationalist. The other thing I'd like to clarify is that the Baath party in Iraq and the one in Syria, again while broadly Arab nationalist and sharing the goal of a united arab world were run quite differently and even opposed each other during a couple of occasions. Syria supported Iran during the Iran/Iraq war and Syria was part of the coalition during the first gulf war. I would like to point you towards asking this question in /r/syriancivilwar , while you'll get a lot of different answers from Baathist supporters and opponents, it'll be a good start for an understanding.

One consideration to be made in understanding so-called Arab or often African socialism is their non-Marxist nature, and shifting importance within the Baathist movement. Socialism in the Arab world is a separate phenomenon, with more conventional links to non-qualified socialism. The term "Arab socialism" (vs socialism in the Arab world) itself is the creation of Micheal Aflaq, who was initially a Communist party member. Certainly, ideas and rhetoric pertaining to social justice, self-management, the role of a vanguard party, and state control of industry formed an important part of this conception, but at the same time, concepts such as internationalism, the primacy of class struggle, the abolition of private ownership of the means of production, etc, did not carry over.

One point to note is that the socialist element of Arab socialism was never thoroughly developed by the main Baathist theoreticians, which makes sense given the rejection of certain key elements of Marxisn socialism, while appropriating the rethoric based upon such conceptions. While the party made explicit in their program such goals as the end of exploitation and use of national wealth for the common good, these were concieved as emerging from state structures, something that Baathism certainly did not ever seek to dissolve. Socialism, like in Marxism, was intended as a means, not towards a classless stateless society (though Baathist rethoric did talk about ending class) but a modernized Arab world. The conception of class and capitalism itself was also unclear, often with such divisions being defined by national character, as opposed to conventional conceptions of class. For example, the party held its national vanguard orientation as proof in itself of its progressive orientation.

During the mid to late 1950s, a msore conventional approach to socialism entered the Baath party, particularly in the Syrian wing, through the works of al Atassi, though he was increasingly sidelined within the party. Jadid's government, which cannot really be termed Baathist, more apprpriately neo-Baathist probably represents the most conventional approach to socialism within the Baath movement, though at this time, the Pan-Arab ideal had largely collapsed, with the increasing role of military Baathists, as opposed to explicitly political figures, seen in the decline of terminology appropriated from the communists in favor of military terminology, most prominent under Saddam. By the 1970s, when the Assad regime was established, and Saddam became the most powerful figure in the Iraqi Baath party, Arab Socialism largely existed as a holdover, and appeal to the masses, again in terms of modernization, welfare etc. By this time, and increasingly in the 1980s and on wards, the left of both the Iraqi and Syrian parties were politically sidelined. Thus, in many ways, Arab socialism bears greater similarities to the rethoric of socialism and social justice emanating from conventional fascist movements, especially in practice. While ostensibly opposed to the same capitalist excess and exploitation that conventional socialism challenged, Arab socialism made room for cross-class collaboration, supported the continued existence of the institution of private property, and did not approach capitalism and class relations on the same basis. While maintaining leftist rhetoric, this was often reduced functionally to state capitalism and welfare, as opposed to clear and broad social transformations. While many Baathist theoreticians, including Aflaq did hope that Arab Socialism would bring about such changes, by the time that neo-Baathists came to power in Syrian and Iraq, the actual program of both parties were significantly removed from their supposed founding principles.

Aflaq, al-Atassi and al-Razzaz are probably your best bets in regards to primary sources, though in my personal opinion, al-Atassi is the most comprehensible. Aflaq is notorious for writing pages upon pages without much content within.

From a narrow historic perspective they were not fascist, because the founders of the party rejected the connection and political overtures from the European fascist nations.

However, on an ideological level, Baathism and fascism are very similar: -Extreme nationalism -Modernist yet focused on ancient nationalistic glories -Anti capitalist yet not marxist (ba'ath party is a bit more explicitly socialist, but would have fit in fine with left fascists like Ernst Röhm) -For one party rule and anti liberal democracy