In the wedding customs of the Hebrews, a man who had become engaged would traditionally leave his bride-to-be in order to construct an addition to his father's house where he could live with his new bride. the father had to approve of the work before the groom was allowed to go and collect the bride to bring her back for the wedding. The bride had to be ready at all times, since the groom would come at any time that he was able - even in the middle of the night. Jesus' saying to His followers, "I go to prepare a place for you" was basically wedding talk that they would have understood given the culture of the time. Some of Jesus' parables, such as that of the wise and foolish maidens, also reflect this custom.
A book that I found to shed great light on the culture of the Bible times (and which is among the sources from which I took the above) is Manners and Customs of Bible Lands by Fred H. Wright. I discussed this material in more detail in my Communion sermon at this past October's Witnesses Now for Jesus convention in PA.