Regularly updated seafood sustainability pocket reference cards from the Monterey Bay Aquarium. For seafood, they offer nation-wide and region-specific reference cards. For sushi there is a nation-wide reference card.
Currently there's no evidence to suggest that salads are a major source of food poisoning in the UK and very few incidents of contamination in pre-packed salads have been reported to the Food Standards Agency in the past three years.
M. McClellan. The New England journal of medicine, 356 (17):
1700-1702(April 2007)PUBM: Print-Electronic; DEP: 20070413; JID: 0255562; 2007/04/13 aheadofprint; ppublish.