If you're not already familiar with this title, it's a detailed history of the Bermuda Hundred Campaign. Several maps of actions like Drewry's Bluff are included, each showing positions of individual regiments involved in the fighting.
http://www.amazon.com/Back-Door-Richmond-Campaign-April-June/dp/0807116726

For people with Alabama connections, this book will also be helpful if your ancestor served in a regiment assigned to Gracie's Alabama Brigade,.