Hi Tanya,
I agree with both Georganna and Knitnak - I use both Adobe Photoshop and Ulead's PhotoImpact. These are definitely the industry standard, especially Photoshop. Flash is a great one as well for creating animated "movies" for websites - Flash has just become an Adobe product - it used to be made by Macromedia.
If you are on a budget, there ARE some open source graphics program you can try. One popular one is GIMP or Graphics Editor and Image Manipulation available at:
http://www.snapfiles.com/get/gimp.htmlSome other open source software for imaging is available from Free Serif Software at:
http://www.freeserifsoftware.com/software/DrawPlus/default.aspBest of Luck with your new venture!
June