There is an interesting post at the Society of Evangelical Arminians today that addresses the objections some of our Calvinist brethren have with the causal impact prayer has in the life of the saint and those he or she interact with. I have long had difficulty grasping why Calvinists in general fail to understand the importance of prayer and the cost of lacking a prayer life. To be sure, this is not a problem limited to Calvinists as the same lack of insight into prayer is found in many corners. I can do nothing but marvel at the notion that failing to pray, to intercede, to petition are mere determined courses of events. How can one avail much if he fails at the means through which God responds? The short article is interesting as is the dialogue on the associated blogs.
One resource I have always turned to regarding prayer is E.M. Bounds, especially his work The Power Through Prayer. It is timeless and truly the work of a saint in love with the LORD.