If you want to get Adobe Photoshop for Free, Adobe gives you a couple of options. If you've seen other options online that give you a link to CS6, that is not the legal way to get Photoshop.
Here is the link to the latest Adobe Photoshop trial
This video will show you two techniques. One is the free trial to the latest version of Adobe Photoshop and a second is a lifetime download of Adobe Photoshop CS2, which Adobe has made available for free.
NOTE: Many current operating systems don't support Photoshop CS2. The 30 day free trial is your best option if you are running a new operating system on Mac or PC.
If you go a different route and download CS6 from a unauthorized source, you run the risk of being caught for illegal software download. Adobe takes this seriously.
Here is the link to Photoshop CS2.