The best graphic design's software is adobe photoshop. Although there are a lot of software are available for you but this is the best solution for you. There are many features available to Adobe photoshop. So a designer can design many things with Adobe photoshop easily. After done your design you can export or save that file many formates like jpg, psd or more. You can also save that file many sizes which you want. There is also a new feature of Adobe photoshop. Now I am going to share with you that is Adobe photoshop's has an extra tools that is you can design a web template then you can convert it to html file. So the Adobe photoshop is a great work place or suitable work place for you.