I've never heard of it (looks sort of similar to lynda.com); if you want to pursue some of their stuff to learn things for your own benefit, which may end up being useful in a job, by all means do so. However it isn't a formal qualification that's accredited in any way and thus it's sort of meaningless in that sense.
You could pursue some of the content on there and then use it in self directed projects or in working situations and then use that as a discussion point for interviews, but listing it on your CV is unlikely to make much difference. Depending on the course you're pursuing, it may not even be that useful - if for example you need an English language qualification, employers etc will look for an actual recognised format (such as GCSE English Language, TOEFL, IELTS etc).