I suggest starting out in Lithographs. You can find some good deals on ebay. I bought a number of Kinkade Authentic Litho's Signed, Numbered and framed for less than it would have cost to have them stretched and framed locally a few years back. I guess I got lucky and bought when a large distributer went out of business or something because very rarely do you see them for sale on there now.
I'm sure there's good money in originals but I look at it abit like domains. I can buy a number of Litho's at wholesale or pay a premium price for an original. And along the same lines there's more people who would be willing to pay $xxx-$x,xxx for a litho over $xx,xxx-$xxx,xxx for an original.
Either way be careful in your buying. There's just as many scammers in that market as there are in any.