I have answers to this question, mostly to do with filtering the flood, and the human need to justify their own opinions, but in the meantime, have a quick read of these five-second-Google-found "how to write album review" articles and tell me what you think.
How to review an album
How to write a music album review
How to review a CD
Most interesting is they all tell the reviewer to listen to the album, multiple times, and take notes, and actually listen.
I'm not sure people actually do that any more.