The music took its lead from the classic rock bands such as Deep Purple, Black Sabbath, Led Zeppelin, plus other bands like Golden Eaaring and Montrose, added a bit of punk ethos/attitude and came up with a new tough sound that had Heavy Metal fans banging their heads and playing air guitar.
Bands to emerge from NWOBHM include: Iron Maiden, Def Leppard, Saxon and Diamond Head. Motorhead and Judas Priest, although being in existence before NWOBHM started, were also considered part of it.
If asked, my default response to NWOBHM is this track:
Trespass - One Of These Days
But I believe I have found another, unrecognised influence: Sweet
Yes, Sweet - the band responsible for throaway 1970's bubblegum pop like Co-Co, Poppa Joe and Alexander Graham Bell. They did achieve a number 1 single with "Blockbuster" (a song which had basically the same riff as David Bowie's "The Jean Genie"), and perhaps they're most well known single was "Ballroom Blitz".
Despite being part of the Chinnichap production line, the band always provided a self-penned track for their B-Sides, and these were usually pretty heavy by comparison.
Listen to tracks like "Done Me Wrong All Right", "Rock And Roll Disgrace" or "Sweet F.A." and you can almost hear the DNA template for NWOBHM.
And here is Exhibit 2 - Promo Video for "Action" from 1975 - Brian Connolly has more than a passing look of Bruce Dickinson about him, especially when holding the mike with two hands and wailing into it.
By the way, have you heard the story (urban myth?) as to why every ceiling has a Sweet Spot?