I try to be very honest in my reviews, and my ratings are based on a 1 to 5 star system:
5 Stars - Highly recommended, read it!
4 Stars - An interesting book, definitely worth reading despite any flaws.
3 Stars - Decent enough in plot, but it has bothersome details that don't make sense.
2 Stars - Only if you're bored; it has some redeeming qualities.
1 Star - Don't waste your time or energy.