I pray that it goes without saying that I would not endorse everything in these links. Dr. Montgomery's commentary is going to take a rather liberal view in regard to the date of Daniel, yet the work can be useful in other ways.
College Press Commentary on Daniel
Volume 1 of John Calvin's Commentary on Daniel
Volume 2 of John Calvin's Commentary on Daniel
International Critical Commentary on Daniel by Dr. James Montgomery
Adam Clarke's Commentary on Daniel
Charles Spurgeon's Sermons on Genesis
Article from Apologetics Press that examines the linguistic evidence for the date of Daniel