The Ten Commandments of Reviewing - post them if you agree and use them yourself
1) Thou shalt point out the parts you enjoy
2) Thou shalt point out the parts you disliked, if any.
3) Thou shalt point out the parts you utterly hated and explain why
4) Thou shalt write with good grammar!
5) Thou shalt not give anonymous reviews, for the authors might want to reply to thine criticism!
6) Thou shalt not flame
7) Thou shalt write a four sentence paragraph minimum!
8) Thou shalt use constructive criticism!
9) Thou shalt review as much as possible, not merely once!
10) Thou shalt voice thine expectations