Calling hours for Michael Chiapperini and Tomasz Kaczowka will be held at the local high school Friday evening and Saturday afternoon and evening.
Police say Christmas Eve gunman William Spengler had apparently mapped out a plan for the attack.
Early on Christmas eve, William Spengler, who spent more than a decade in prison on murder charges in the 1980s, set a blaze in his home near the shore of Lake Ontario.
The 62-year-old man then lay in wait.
When fire crews arrived, he opened fire with a Bushmaster assault rifle, which police say was identical to the weapon used in the recent school shooting in Connecticut.
He also had a revolver and a shotgun.
Webster police chief Gerald Pickering told reporters that Spengler was "prepared to go to war" with first responders.
Police say they've also found human remains inside Spengler's home. It's believed to be the body of Spengler's 67-year-old sister, though the identity has not yet been determined.
Authorities also recovered a note the gunman left, saying that he planned to burn down his neighborhood and "do what I like doing best, killing people."
In all, seven homes were destroyed in the blaze that spread when crews were unable to battle the fire.
Residents began returning to the ravaged neighborhood on Christmas day.
Many had been evacuated by a SWAT team using an armored vehicle.
The shooting comes as Congress and New York's legislature are debating new gun control legislation that would likely focus on assault rifles and large ammunition clips.
(The Associated Press contributed to this story.)