I believe I have made a plug for this book before. But I feel I should do it again, since I have given this book a thorough read now. Before I just loved it because of a presentation I heard about it by the author.
I recommend Dating Game Secrets For Marrying A Good Man. I realize the book seems directed at women (marketing decision I believe), but the principals within are great for any single. There are three parts to the book: Be Safe, Be Confident, Be Successful. My favourite part of the book is the 3-date rule. These rules can help men and women identify someone who is potentially abusive or manipulative.
If you are single, and struggling, pick this book up.