The CBS All Access video on demand is a popular and growing video on demand service throughout the US, it offers its users not just 1000s of current and old tv series but live sports, news and tv, from local stations and all the CBS network channels. It is unfortunately only available in the US, however this often makes it easier for streaming services to obtain licensees/contracts for more and better films/tv.
The sign up for your one week trial is fairly straight forward, once you have clicked the green button labelled "get free trial" at the top of this page you will see it is just a couple of easy steps before your watching your favourite shows.
If your wanting to see a little more of what the service has to offer you can take a small tour before you sign-up.
You may find that most of the tv you watch is available through the CBS all access network. Like many watch less and less tv through your cable box and gradually replace it with a service like CBS as it offers the live tv as well as unlimited tv shows any-time anywhere, through tablets smart-tv, game console and roku devices.