For best results, when you freeze corn choose only the most tender ears at their peak of freshness.
How to Select and Buy Fresh Corn
Harvesting Corn: Pick your corn during the milk stage, which is when the kernels are plump and the silks are dry and brown. The kernels should be tender and filled with milky juice when pierced with a fingernail. The kernels should be tight and fill the cobs to the tip. Cook immediately after picking or refrigerate if necessary as the sugar in corn quickly turns to starch, which will result in tough kernels. 
Purchasing Corn: Look for bright green, moist husks with stiff, dark, and moist silk. Corn loses more than 25% of its sugar within 25 hours of harvesting so purchase your corn directly before you intend to use it. 
Preparing Corn for Freezing
Husk the corn removing all silks. Wash in cold water.
On the Cob: You can freeze the entire ear or cut it into smaller sections. For smaller sections, blanch for 7 minutes. For the entire ear, blanch for 11 minutes. Allow to cool completely before packing.
Whole-kernel: Blanch the entire cob for 4 minutes then shave the kernels from the corn.
On-the-cob: Package cooled ears in a freezer safe bag. Seal. Freeze.
Whole-kernel: Place your blanched kernels in a freezer safe bag allowing ½” headspace. Seal. Freeze
Storing frozen foods at 0° F or lower will help to retain color, flavor, texture, and vitamin content. Freezing for extended periods will cause the quality of your frozen foods to deteriorate. 
 “Harvesting Vegetables.” WSU Gardening in Western Washington. N.p., n.d. Web. 4 Apr. 2012. <http://gardening.wsu.edu/library/vege022/vege022.htm>.
 “Massachusetts Corn.” Find farm fresh, locally grown produce from farms in northeastern Massachusetts.. N.p., n.d. Web. 4 Apr. 2012. <http://www.buyfresh.org/findlocalfood/massachusetts-corn>.
 “National Center for Home Food Preservation | How Do I? Freeze.” National Center for Home Food Preservation. N.p., n.d. Web. 4 Apr. 2012. <http://nchfp.uga.edu/how/freeze/corn.html>.
 “Freezing and Food Safety.” USDA Food Safety and Inspection Service Home . N.p., n.d. Web. 4 Apr. 2012. <http://www.fsis.usda.gov/Factsheets/Focus_On_Freezing/index.asp>