Complex sentence: He first entered the world of publishing in 1994 with a powerboating magazine now called RIB Magazine, and is currently owner and managing director of Oyster House Media, publishing "Bass Guitar Magazine" alongside Drummer, Acoustic and Guitar Buyer magazines.
Split into simpler sentences: He first entered the world of publishing in 1994 with a powerboating magazine now called RIB Magazine. This company published "Bass Guitar Magazine" alongside Drummer, Acoustic, and Guitar Buyer magazines.