1 Peter is another "general letter." Like James, Peter addresses this letter to a wide range of places in what is now modern day Turkey: Pontus, Galatia, Cappadocia, Asia and Bithynia (1:1). This list seems like a somewhat strange audience for Peter to address, given that we have no record of Peter ever visiting these places. Of them, we know Paul ministered in Asia and Galatia.
There is also the curious comment tucked at the end, that this letter was written, "with the help of Silas" (5:12). Silas was of course Paul's main coworker during his years of ministry in Asia and Galatia. If Silas had much to do with the writing of this letter, it might explain not only the audience, not only the Greek,  but it might explain why some of 1 Peter sounds a little like Paul. 
1 Peter was written during a time of general persecution. In the previous chapter on James, we mentioned that the Romans did not have a general policy on persecuting Christians. But general oppression must have been common enough to be expected pretty much everywhere. Peter signs off from "Babylon," suggesting that the letter was sent from Rome.
Use of the word "Babylon" raises questions about the dating of the letter. Babylon was of course the empire that had destroyed Jerusalem in 586BC, and we know that Jews in the late first century applied this word to Rome after Rome destroyed Jerusalem in AD70.  But Peter had already been dead for at least a couple years by the time this event happened.
Tradition has it that Peter died at the hands of the emperor Nero. The persecution of AD64 is a favorite, but in theory Nero could have killed him anytime up to the time he committed suicide in AD68. In the last three years of Nero's reign, the Jewish War had begun, where the Jews tried to retake Israel from the Romans. It is at least plausible that the Jews would already have called Rome, "Babylon," that early.
So the years AD66-68 seem the best guess for the date of 1 Peter if Peter primarily stands behind the letter. Another suggestion is that it was more written by Silas not long after Peter's death, possibly with content from Peter when he was alive. Then a date not long after AD70 would be plausible. The truths and inspiration of the letter stand whichever option you pick.
One of the key messages of 1 Peter is that "it is better, if it is God’s will, to suffer for doing good than for doing evil" (3:17). If Christians are going to suffer, then they had better not suffer because they are truly criminals. It is an honor to suffer when you are innocent. If you suffer for wrongs you actually did, you are just getting what you deserve.
One of the best known verses in 1 Peter pictures a situation where Christians are brought before a governor or Roman official and interrogated about their belief that there is another king other than Caesar. "Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have" (3:15). The idea here is not to be able to rationally defend your faith with quotes from C. S. Lewis and Ravi Zacharias. The point is to be ready to confess that Jesus is your Lord before rulers, even if it means you face death like Paul and Peter did...
 Acts 4:13 describes Peter as "unschooled," a word that can mean illiterate at least in the sense of not knowing Greek. The Greek of 1 Peter, however, is much more advanced than, say, the Greek of John.
 Like James, 1 Peter does not have Aramaic-speaking Jewish flavor we might expect after reading Paul's letter to the Galatians.
 Revelation would be a case in point (e.g., 17:5).