I go to sidereel.com, which has links to sites that stream tv shows. If you search for a particular show, it will list all the episodes, and you can then choose which one you want to watch. I always choose a link to megavideo since it seems to be the most reliable and fast. American shows are usually available about 8 hours after they air in the US.
I did choose to register with megavideo.com since they have a daily limit of how much you can watch since my kids kept using up our time before I had a chance to watch my shows in the evening. To me it's worth every penny. However, if you only watch about an hour of tv a day, you can do that for free.
If you take the time to register on sidereel, you can make a profile that tracks all your favourite shows. It will tell you when a new episode is airing and will take you directly to its link.