In my first job after college, I was a news editor on an internationally distributed magazine called The Comics Journal, a long-running publication devoted to the comic book industry (as well as sometimes newspaper cartoonists) which featured one or two long-form (20-40 page) interviews with writers and artists in each issue. These interviews usually covered the entire life and aesthetic opinions of the creator being interviewed, and so required an intense period of research beforehand in order to become thoroughly versed in the public lives and careers of the interviewees, as well as to find the best possible artwork and photographs to accompany the text. This research required poring through old magazines to dig up journalistic coverage of significant events in the career of the interviewee as well as reading every publication the writer and/or artist creatively contributed to. I got the chance to conduct five of these interviews, three of them being the main selling point on the cover of the magazine.
I was later tickled to find out that one of the five cartoonists I interviewed for The Comics Journal, Rick Veitch, had a dream about the experience of being interviewed by me over the course of weeks and devoted some pages of an issue of his comic book Rare Bit Fiends to this dream. In it, I was the person being interviewed (rather than him), while he was a world-weary soldier overhearing snippets of my interview in between battles. Here's one page from that story:
In addition to these interviews I conducted for the magazine, I also edited a sketchbook feature in which I sent letters to artists I admired and asked them to send copies of artwork from their personal sketchbooks to be run in the magazine, and wrote several articles. I also later conducted a long-form interview on my own website with the "Ren and Stimpy" animator / comic book cartoonist / fine artist William (Bill) Wray.