I know I already produced a list of what marine species are okay to eat/not eat, but the MCS have produced many web pages to help people to buy more environmentally smart.
http://www.fishonline.org/buying_eating/purchasing_guide.php
- this page is a purchasing guide which instructs what is best to buy and when.
http://www.fishonline.org/search/simple/
- this page is a basic search engine where you can look up your marine species of choice and find out all the facts you need to know about it, before trotting off to the supermarket.
http://www.fishonline.org/information/faqs/
- this is a page of FAQ's all fully answered with links.
http://www.fishonline.org/information/MCSPocket_Good_Fish_Guide.pdf
- this is the pocket guide for simple information, fast.