A good start is to purchase "Adobe Photoshop CS5 Classroom in a Book" and work through it in Photoshop with the images on its enclosed DVD. If you don't have the CS5 version of Photoshop, purchase the book of the same name except replace the version number in the book name with the Photoshop version you have.
Another good learning resource is watching the tutorial videos of the latest versions of Photoshop on the Adobe TV website.
Some great learning resources online that have a low-priced fee attached are in the related links.
Also check out instructor-led training options in your state in the Adobe Partner Finder on the Adobe website at the related link.
TIP: Check out the new "Creative Cloud" on the Adobe website for info on the new subscription-based access to a huge package of many different Adobe softwares - $(49.99/mo or 29.99/mo education pricing).
You don't need any other software to operate any version of Photoshop. The more RAM and HD space your computer has will improve your experience.
Photoshop Elements is Photoshop but with less features, so Photoshop is better but it is professional level software. For home use or to get started Photoshop Elements is OK.
Photoshop 3.0
what is photoshop?
No, photoshop is not the law
Well Photoshop Elements is basically Photoshop, but that everything is already ready there. it's like easy version of Photoshop.
You can't. You need brushes photoshop 7 brushes for photoshop 7.0
By using photoshop of course
No Photoshop CS5 and Photoshop Elements are separate programs.
Adobe PhotoShop is an image editing application. You can get it from:http://www.adobe.com/products/photoshop/photoshop/there it costs $700 USD.
Yes, Photoshop can be downloaded online. Visit photoshop's official webpage for details on how to do this. Photoshop will cost several hundred dollars.
psd is a photoshop extension and can be opened with photoshop or photoshop elements.