Fulham's first win in eight Premiership games was something of a slow-burner, but after a first half that failed to catch light, the game exploded into life after the interval.
By the time Obafemi Martins latched on to a lobbed pass from Nolberto Solano to score a late consolation goal for the visitors, Helguson's opportunistic opener and McBride's clinical close-range second, had long since made the game safe for Fulham, who were good value for the points.
After a lacklustre midweek performance against Sheffield United in which they failed to muster a single shot on target, Fulham looked intent on rediscovering their attacking impetus from the outset.
The initial signs were promising. Shrugging off a pre-match setback when Antti Niemi was injured during the warm-up, had to be replaced in goal by Czech Jan Lastuvka, the Cottagers began brightly, dominating possession.
Wayne Routledge, full of trickery along the left wing, was at the heart of all that was good about Fulham going forward and with frontman Helguson in lively mood alongside McBride, the Cottagers were soon pressing for an early breakthrough.
But new signing Oguchi Onyewu was a robust presence at the heart of the Newcastle defence and for all the home side's enterprise, clear-cut openings were at a premium early on.
Fulham's best chance came late in the half, when Stephen Carr attempted a dangerous back-header to goalkeeper Steve Harper that was almost intercepted by the lurking Helguson. Moments later Routledge blazed over from the edge of the area.
For Newcastle, Kieron Dyer sliced an early chance narrowly wide, but it was the stroke of half-time before the visitors mustered another meaningful attack, Obafemi Martins connecting with a James Milner corner to force a save from Lastuvka, before follow-up efforts from Steven Taylor and Dyer were blocked.
The second half quickly brought change. When Carr delivered a 49th-minute throw in to Nicky Butt on the left-hand touchline, there seemed little immediate danger for Newcastle.
But the former Manchester United man, under pressure from a glut of Fulham midfielders, attempted a suicidal back pass to Harper and Helguson was there in a flash, latching on to the loose ball to fire home his fourth goal of the season.
Fulham quickly had opportunities to extend their lead. Simon Davies got his head on to a Liam Rosenior cross to force Harper to tip over and moments later defender Carlos Bocanegra planted another firm header into the Newcastle goalkeeper's grateful grasp.
Newcastle were living dangerously, and when Titus Bramble brought down Helguson after the Icelander had broken clean through, they looked to have blown it.
Referee Phil Dowd ruled that the Newcastle defender was not the last man and Bramble received no more than a booking, but worse was to follow for the Magpies.
With 67 minutes gone, Coleman introduced Papa Bouba Diop to the fray. The Senegal international's muscular presence quickly had an unsettling effect on the Newcastle defence and he quickly put his physique to use, collecting the ball on the edge of the area before shrugging his way along the byline, defenders in hot pursuit, to cut back for McBride, who slotted home clinically.
Martins swooped in injury-time to score his eleventh goal of the season, but it was too little, too late for Glenn Roeder's men.