Blender is free opensource software which everybody can download at blender.org and use for free for any purpose. There are plenty of tutorials on community sites and elsewhere on the web from the basics to advanced topics.
3dmagix is a package offered by a guy who calls himself Cody Landon which offers the same Blender commercially plus a set of tutorials, which most probably have been ripped off the web. If you want to pay for his package, go to 3dmagix.com (I don’t see the point, but you may wish to do so). The site is good reading for those who are interested in manipulatory marketing techniques for the naive.
Warning: the site contains a lot of unverified information AND copyrighted artwork used without the authors’ permission.
If you want some more info and to get familiar with the debate around this issue, you can read these posts:
Honestly, the site makes me sick – I sometimes admire marketing techniques, but this garbage is just too much. Apart from being fraudulent, it’s just so damn cheap…