Their practice of only allowing you to cancel Xbox Live by phoning in, NOT online is designed to put a roadblock in your path of controlling you account. Also, their retention of your CC number and automatic renewal of services is shady at best, again requiring you to phone them to cancel. These practices are annoying and frustrating. I would advise potential subscribers to NEVER give them your CC number at all ... purchase the cards for Xbox Live services and points.
It's a good site. Between what Xbox has to say and show you and the forums there is a wealth of information. You can download material for the Xbox on the website and the next time you turn your Xbox on it will download it. All together I would say it is a very safe site. Just watch out for young kids because as in video games there is some violence.