Here's an article with relevance for lawyers on either side of a products-liability case: "Complex Products Liability: The Plaintiff's Perspective of Evaluating and Preparing a Winning Case," by LaBarron Boone, Kendall C. Dunson, and Rodney Barganier (pdf).
Although the article appears to be a companion to a spoken presentation, one of its sections, "How to Prepare a Products Liability Case," contains some good discovery tips. Interrogatories should be narrow and specific (good advice for any type of case). Experts should be asked to provide input in drafting initial discovery. And corporate representative depositions should be the rule, not the exception.
I also liked the section about deposing design engineers, which included a useful explanation of the "order of design preference."