Wayne Grudem, 1 Peter, The Tyndale New Testament Commentaries (Grand Rapids: Eerdmans, 1988). A good basic commentary that does not skirt around the difficulties.
A 62-page paper that is freely downloadable examining the structure of 1 Peter and applying it to the church situation in Bantu Africa.
The Net Bible
A freely available modern translation with excellent notes on the meanings of difficult-to-translate phrases