If you want to create promo materials, then Photoshop would not be a good choice, as it's purpose is bitmap image manipulation. Much better choice would be Corel Draw, Adobe Illustrator or something like that(vector based graphics).
Free (and quite good) alternatives for Photoshop is Gimp (
www.gimp.org), and for Corel Draw or Adobe Illustrator that is Incscape (
www.inkscape.org/) or Creative Docs.NET (
www.creativedocs.net).
If you want to create multi-page documents then also take a look on Scribus (
www.scribus.net).