I always use Adobe Illustrator for my artwork, but it depends on what sort of artwork you are planning on doing. If you are doing lots of logos, you'll need something like coredraw to plot all of your images.
You can use illustrator and draw directly onto a new page, or scan an image in, and trace over the design. Illustrator CS2 has an auto trace feature, but it does not always trace an accurate enough line, so you may need to tidy that up! I always trace by hand, so I know what I am getting!
Hope that helps
