First, Owen Strachan--a former intern under Mark Dever, an assistant under Al Mohler, and a blogger at Consumed--recently completed his MDiv at the Southern Baptist Theological Seminary and is now a PhD student a Trinity Evangelical Divinity School and the managing editor of Trinity's Henry Center. He has written a helpful three-part series on the Seasons of a Seminarian (Beginning, Middle, End). Not everyone's experience will match Owen's, of course, but this is a helpful overview of the sort of things many experience in seminary. (There's also a helpful podcast interview with Owen related to this topic.)
In addition, I've found the following articles particularly helpful in the past for thinking about seminary and how to prepare for it:
B. B. Warfield, The Religious Life of Theological Students (1911)
Helmut Thielicke, A Little Exercise for Young Theologians (1962)John Frame, Learning at Jesus’ Feet: A Case for Seminary Training
John Frame, Studying Theology as a Servant of Jesus
Reformed Theological Seminary’s pre-seminary reading list (short version and extended version)
