Once Angel comics started drawing readers in IDW decided to do some one shots on the characters that didn't have fangs. Let's start on the Irish characters. Some spoilers for the tv show and the comics.
The Who: Connor has the sort of history you'd expect of a character in comics rather than something that spun off of television. He was born out of an impossible union of vampires. See in the ATS/BTVS universe vampires can't have kids so his creation drew a lot of attention. His mother was the vampire known as Darla who sired Angel, Connors' birth father. Some time after he was born Connor was taken and raised in another dimension by a vampire hunter who swore revenge on Darla and Angel(us). Needless to say Connor had some anger issues with his birth father when he returned as a teenager. Bad stuff happened and he lost the will to live. To save his son Angel made a deal to overwrite Connors' memories and give him a proper family. Connor returned in the last season and regained his memories. Now better adjusted he fights demons and strives to be a hero like his dad.
Takes Place: During season 5 after Origins.
The comic it's self: Connor is in college trying to write out his (fake) family tree and dealing with what he inherited from his real father. The powers, urge to help others and even a violent streak. Unfortunately the writing is awkward, the villain is forgettable and the art work isn't right for this story. There are better stories of Connor in comics, namely Angel After the Fall, making this one all the more disappointing in comparison. While he may not have lead in those stories he had a pretty impressive role showcasing why he mattered to the series.
The Who: Allen Francis Doyle was a half-demon that the powers that be gave visions. He was charged with finding Angel and getting him started on his path towards redemption. Along with Angel and Cordelia he formed Angel Investigations to "Help the helpless." Doyle fell pretty hard for Cordelia but couldn't strike up the nerve to ask her out due to his fear of her rejecting his demon half. His own path of redemption was due to his struggles to accept himself and blaming himself for the deaths of other demons due to his refusal to help them. Using his powers to aid Angel's fight and inspired by his friends he found it within him to save others at the cost of his own life. Before doing so he kissed Cordelia goodbye transferring the visions to her. Doyle's death affected Angel and Cordelia deeply prompting both to make the right choses for the greater good. For fans Doyle's death will always be especially painful due to actor Glenn Quinn's real life death.
Takes Place: Post-Buffy season 3/pre-Angel season 1 to the first episode.
The comic it's self: This comic was something of a pleasant surprise for Angel fans since we didn't expect to see a comic focused on this character. Since Doyle didn't really get too many episodes in the first season there's a lot of things to explore. Right off I like that it mentions that he was married and a school teacher. It's easy to forget that he had a normal life before everything turned upside down. This starts right after the visions begin and Doyle's trying to understand what it all means. It's one of the better spotlights that showcases what makes the lead interesting and properly fills in the gaps. From this we see why Doyle's a hero but doesn't think he is and how he's already learning from his visions. It also has a nice Roseanne related gag. (Glenn Quinn played Mark Healy.) Plus the art is decent and mostly looks like the actor.