I recently finished Praying Backwards, by Bryan Chapell. The name sounds a bit odd, but it turns out it makes sense. Praying Backwards talks about how learning to pray "in Jesus' name", and making this concept central (even first!) in our prayer, can "transform your prayer life".
This book is really an excellent discussion of prayer, deals a lot with the theology of prayer, and gives a lot of practical help for how we ought to pray and what our attitude ought to be in prayer. One central point is that prayer is not primarily a way to get God to do what we want, yet God does still hear our requests. Prayer needs to always be offered "in Jesus' name", which doesn't necessarily mean that we say those words, but that we begin our prayer with that concept. In practice, that means that we need to be praying for the glory of God, and coming to God based on the work of Jesus Christ on our behalf. That includes his past work on the cross, but also his present intercessory work for us.
I'd been praying some recently that God would teach me how to pray more effectively, and I can say that this book has been a step in the right direction. Thankfully, I think I've been exposed to most of the concepts in here before (see the bottom of the review for a couple other good references for the topic), but this proved a much-needed reminder, and it is great to have all of this material in one thin, easy to read volume.
Overall, I recommend this book highly, but I do have one caveat: Don't read just part of the book, and don't pick and choose chapters. The whole book presents a balanced and thorough view of prayer, but I think some of the chapters don't quite give the whole picture on their own.
To give just one example, Chapell has two helpful chapters laying out some principles to know whether what we're praying is in God's will. He says we need to stay within two fences -- the first is the fence of righteousness (which we know from God's Word) and the second, the fence of Christian prudencce. In his chapter on the fence of righteousness, he points out that things are only sin if they are prohibited (either implicitly or explicitly) by Scripture. From this, he concludes it is possible that, in decision making, there may be multiple right choices, and we ought to pick the one we prefer. He likens such decisions to having multiple apples to choose from; it's not the case that one apple is good and the rest are evil. Chapell gives the example of choosing a job or who to marry as decisions that might fall into this category (multiple right choices). However, in the following chapter, he discusses the "fence of prudence", he goes on to discuss some principles which do help making such decisions. One is that we ought to examine ourselves. He gives the example of his own decision to go to seminary instead of law school. He weighed the two against each other, and realized that if he chose law school, he was choosing for selfish motives, so the proper decision was the one made with right motives. He also says that it's important to seek counsel from godly advisors, and mentions that God often calls us to apply Scriptural principles when there is no obvious right or wrong (but where Scriptural principles do apply and will show us the way to go).
If you read only the chapter on the "fence of righteousness", I think it would be easy to come away with the idea that, in many or most decisions, we are free to do as we please, because Scripture doesn't give explicit guidance. The following chapter makes clear that this isn't what Chapell is actually saying. There are some other instances where similar things occur, so I reiterate: If you read this book, read the whole thing, in order to get a balanced, Biblical view. Don't just read parts. There are a few minor comments Chapell makes that I don't entirely agree with, so, as always, you should read with discernment, but as a whole, the book is excellent.
Overall, I highly recommend the book. I've read other books which touch on some of the same issues, but this is a book entirely on prayer, so it is able to cover the issues more thoroughly, and does an excellent job. If your prayer life needs help, this is a good place to start.
I mentioned that I'd encountered many of the concepts here before, so I want to briefly recommend a couple other books this reminds me of. One is J. C. Ryle's excellent book "Practical Religion". If you don't have a copy of this book, it is really a must-have. This is a reasonably hefty volume (around 500 pages in 21 chapters), but is relatively easy going, as each of the 21 chapters is stand-alone. It covers a lot of practical Christian topics, like prayer, Bible-reading, communion, happiness, etc. I'll probably write a longer review of it at some point, but the 30 page discussion in here on prayer covers some of the same concepts Chapell hits.
Another is Wayne Grudem's Systematic Theology, which has a chapter on prayer. Additionally, the chapters on the Scriptures make abundantly clear how we are to know God's will and how we are to make decisions, which are some of the issues Chapell touches on here but doesn't cover as exhaustively. Unlike many systematic theologies, Grudem's is immensely practical. If you've got it, it's worth reading the chapter on prayer. And if you don't have it, it's worth getting as a reference.
Finally, I'd also like to mention G. I. Williamson's book "The Heidelberg Catechism: A Study Guide". Some of the questions in the catechism cover prayer, and the Lord's prayer, and this book has a reasonably detailed discussion of each of the questions, their answers, and the implications.
I don't mention these three to deter you from reading Praying Backwards. It's definitely worth reading, and I highly recommend it. Rather, if you read it and are looking for more good material on prayer, check these three out. Or if you already have one of these three on your shelf, but haven't read it, they're worth reading.