"Step 1: Cocoa Content
When buying dark chocolate look for 70% cocoa content. Very dark chocolate can be an acquired taste, though, so play around with different brands until you hit on one you like.
Step 2: Fat Content
The type of fat listed in the ingredients is important. You want to avoid products that contain palm oil or coconut oil or milk fat, and choose ones that are made from "cocoa butter". Even though they're all saturated fats, "cocoa butter" has a neutral effect on cholesterol levels, while the other two can raise your blood cholesterol." [-joy's healthy bite]