Reddit reviews Understanding Marijuana: A New Look at the Scientific Evidence

There's a book called Understanding Marijuana by Mitch Earleywine that does a fantastic job of doing exactly this. His writing is very unbiased and he references many studies that have been conducting on the effects of marijuana, including how they were conducted so you get an understanding of how the conclusions were formed and the scientific evidence to back it up.

Check this book out: Understanding Marijuana: A New Look at the Scientific Evidence