Research has shown that the cons of homework outweigh the pros. There is absolutely no correlation of completing homework to having higher standardized test scores. Students also have a much more stressful life with the addition of homework and parents seem to agree. They worry about their child's happiness as it is hidden behind the mountains of homework. We all know that the average teenager needs about 8 hours of sleep, but it's hard for them to sleep this much if their homework keeps them awake for several hours on end. Homework also gets in the way of family bonding events like family dinners, shopping with your mom, or throwing the football with your dad and siblings. The rate at which kids read for enjoyment decreases because of the immense amount of homework thrust upon them.
http://www.usatoday.com/news/opinion/editorials/2006-07-02-opposing-view_x.htm: this article is the opposing view to one of the articles listed on the pros page. This stresses the unimportance of homework showing that countries who do better than us in math and science, barely assign homework in the first place.
http://www.parenting.com/article/too-much-homework-bad-for-kids: shows the signs when kids start hating school because of all their homework. Kids become too "bogged down" with homework to enjoy being kids.
http://www.time.com/time/magazine/article/0,9171,1376208-1,00.html: further more stresses the unimportance of homework with statistics from books, where authors have looked at studies on the topic of homework.