You can find detailed information on about any agricultural commodity in Minnesota by going to the University of Minnesota Extension Service website, http://www.extension.umn.edu/farm.
There's detailed producer-related information on websites for dairy-- http://www.extension.umn.edu/dairy, beef--http://www.extension.umn.edu/beef, and swine-- http://www.extension.umn.edu/swine.
A popular crops newsletter, Minnesota Crop eNews, http://www.extension.umn.edu/cropenews, has the latest hot topics and seasonal information. There's also the Center for Farm Financial Management, http://www.cffm.umn.edu, which includes a link to the National Ag Risk Library.
Other websites include soybean production, forages, sustainable agriculture, weed science research, climatology, horses, and land economics. There are dozens more, including crop variety trials, manure and odor research, and the Upper Midwest Hay List. Just click on http://www.extension.umn.edu/farm to get started.