A short but powerful book written about 100 years ago by EM Bounds, a Methodist minister. It's a bit heavy - not a book to be read at one sitting - but contains a lot of sound advice for Christians everywhere.
There are many examples of praying people, both in recent history and in Scripture, with clear results from their devotions. There is inspiration, encouragement, and instruction too. All Bible verses are quoted from the Authorised Version, adding to the slightly old-fashioned feel of the book, but I found it well worth persevering.
As with any book of this type, I wasn't sure I agreed totally with every word - and yet, overall, I found it very useful and encouraging. Recommended.