In preparation for the premiere of the new series of Torchwood, Starz have released character introductions on various websites across the internet! They each include a back story for the characters as well as preview clips from the series. Below are a list of links for the introductions:

io5 has Captain Jack’s video
TVGuide has Rex Matheson's video
NYMag's Vulture has Gwen Cooper's video has Jilly Kitzinger's video
Insider EW has Oswald Danes' video
USA Today has Esther Dummond’s video