I don’t know how others do research for stories, but I use a combination of reference books and Google. For me Google is a supplement to answer questions after having read the reference books rather than an initial go to.
In writing stories which I hope will be accepted by Black Coat Press‘ Tales of the Shadowmen series I have been reading a lot as it is important to get details of characters and their timelines right. I was aware of many of the characters in French science fiction and pulps but hadn’t read too many of the stories in the originals. The first starting point was Jean-Marc and Randy Lofficier’s two Shadowmen reference volumes – both from Black Coat – and the Crossovers books from Win Scott Eckert and Sean Lee Levin. However as the stories featuring the characters are constantly developing by other authors and devotees of the Wold Newton Universe are constantly finding new links to other media, keeping up does involve lots of visiting websites and writing notes. I’ve attached my list of reference books used in the process in case anyone else is travelling on the same journey and would welcome further suggestions. Unfortunately the Lofficier’s giant volume on French science fiction, fantasy and horror is out of print and there don’t seem to be any copies available at a reasonable price online. Luckily their Cool French Comics site has a regularly updated biography and timeline for most of them.
One reason the research is essential is that the work of fitting in characters to the overall WNU timeline often means changing the dates of the original stories. This is sometimes because of internal inconsistencies – Rouletabille’s first adventure: The Adventure of the Yellow Room, is supposed to be set in 1892, but later books suggest a better date would be 1902. Devotees of the Sherlock Holmes canon know how casual Dr Watson was in chronicling his friend’s continuity – sometimes to protect clients and sometimes because he just forgot. One could suggest it is just bad form for authors not to consider the needs of writers 100 years later.
The trick in writing crossover stories for me is to concentrate on the story and characters and avoid the temptation to forget the plot and write out the research. While there are now thousands of characters that exist in the same WNU that doesn’t mean it is likely they would have had adventures together even if they were in the same time period, or that shoehorning them together makes for a coherent story. There are some strange team ups that work such as Peter Cannon’s Scream for Jeeves, but others that seem a little forced. Hopefully that is a trap I will avoid.