1. What Families altogether were involved in that war? I know it was much more thanthe NY FAMILIES

2. What Families had sided with Maranzano? What Families sided with Joe?

I'm not clear on all the details, but I believe that the division of NY into "territories" and the creation of the five "families" were a result of the war.

Well, this is fairly complicated, BofB, so please bear with me:
There were already five Mafia families of Sicilian origin in NYC in the '20's that had sprung up more or less spontaneously. The most powerful was headed by Joe (the Boss) Masseria. As a way of expanding his power, Masseria interjected himself in a quarrel between Al Capone, a Neapolitan, and Joe Aiello, a Sicilian, in Chicago. To make a long story short, Gaspar Milazzo, a Sicilian Mafioso from the town of Castellemmare del Golfo, objected and was killed by Masseria. Castellemmarese in other cities (notably NY and Buffalo) banded together to fight Masseria. The Castellemmmarese were led by Salvatore Maranzano. While this war technically didn't engage the other NYC families, Maranzano, crafty fellow that he was, called for others to join his cause. He prevailed by cajoling and torturing Charlie Luciano, Masseria's underboss, to betray Masseria.
After arranging for Masseria's death, Maranzano called a meeting of some 600 NYC Mafioso and, as plawrence alluded, officially formed them into families, with a structure of Dons, caporegimes, soldiers, etc., modeled on his beloved Roman legions (Maranzano knew Latin, was fond of quoting Cicero and of comparing himself to Julius Caeser). Then he made the fatal mistake of declaring himself capo di tutti capi,and demanding a monthly tribute from each and every Mafioso. This didn't sit too well with the younger guys, who looked to Luciano to help them. Luciano arranged for Masseria's assassination. Instead of declaring himself the new "boss of bosses," Luciano formed The Commission, which accomplished the same thing but gave others a say.
Two other points that may be of interest:
--The guy who organized both the Masseria and Maranzano hits was Luciano's boyhood chum--Meyer Lansky. Bugsy Siegel was one of the Masseria shooters; the Maranzano hit team was led by Samuel (Red) Levine.
--Even as Luciano was preparing to have Maranzano killed, Maranzano was preparing to have Luciano killed. Maranzano had hired Vincent (Mad Dog) Coll, a noted free-lance Irish killer, to whack Luciano. Coll was in the lobby of the Grand Central Building (where Maranzano had his offices), waiting for an elevator to take him up for his last instructions, even as Levine & Co. were shooting and stabbing Maranzano to death upstairs.

I agree, very well said.

Thank u Turnbull. By the way I need to correct ya on something. Lucky (Charlie) wasn't an underboss be4 Masseria was killed. I read in many Mob history sites that he was a Capo