I haven't counted, but I guess that the Ninth Doctor probably has generated less officially sanctioned spinoff material than any of the others (and the Eighth probably the most, so far). This collection brings together the four Ninth Doctor comic strips which ran in Doctor Who Monthly from issue 355 to issue 364, plus also a story from the 2006 Doctor Who annual.
The comic strip form, at least under DWM's circumstances, doesn't give the writer much space to do things in - only about nine pages per installment. The two single-shot stories, "Art Attack" by Mike Collins and "Mr Nobody" by Scott Gray, both have the very simple plot of a guest character realising his destiny as a result of interaction with the Doctor, Rose and an alien menace. Two of the other three stories, "The Love Attack" and "A Groatsworth of Wit", are by Gareth Roberts, and both are alien invasions of London at different times in the past - the 1960s and the 1590s, with the Doctor thwarting alien plots to change history (either by altering the score of the 1966 World Cup final and or by killing Shakespeare).
The standout piece is also the longest, Rob Shearman's "The Cruel Sea", set on a mysteriously underpopulated cruise ship on the seas of a future Mars. The plot is basically the same Doctor-and-companion(s)-defeating-evil story which has sustained Who since the Christmas of 1963, but Shearman takes the opportunity to probe more deeply into the relationship between the Doctor and Rose, and into how Rose's life might have gone otherwise. There were also several moments in the story that could only really be done effectively in the graphic medium. (In ten years' time, I shall dig this out for the image of the thirty-something Billie Piper to compare with the real thing.)
The DWM strips are all drawn by Mike Collins, though they vary rather in how well he captures the Doctor and Rose - oddly, I think he does it best in the second story, "Art Attack", which he also wrote. The Annual story is drawn by John Ross.
I am a bit puzzled as to the correct bibliographical attribution of the collection. The colophon gives as editors the then DWM editors Clayton Hickman and Scott Gray, but I've seen Andrew Pixley's name mentioned in online sources too. I'm sure someone can enlighten me.