While we have had many threads asking where to buy fish, there have been no postings about what to look for, what kind and type are good for you and what kinds not to buy and the differences between fish.
I have found the following sites rather helpful and educational:
Fish Watch: U.S. Seafood Facts from NOAA
Updated 4 months ago | 3
Updated 3 months ago | 21
Updated 2 months ago | 11
Updated 1 month ago | 4
Updated 12 days ago | 3