One of the great resources for curious artists are the auction catalogs. You can view marvelous works by the biggest names and some you have never heard of. I used to pay hundreds of dollars a year for these catalogs but now I can view them online. With these online catalogs you can zoom into the images and see them in very high detail. These images are educational and inspiring. Here is an image from an upcoming auction, the Impressionist / Modern Day Sale at Christies, London on February 8, 2012.
The image is by Alfred Sisley, "Saitn-Mannes," 1885. This is a blow up of the oil on canvas, 21 1/2 x 28 3/4. Should you want to take it home, it is expected to bring a price in the range of $600-900,000.
View Alfred's little gem here in greater detail: Christie's Feb 2012 sale, Alfred Sisley
While you are there you can sign up for your choice of upcoming sales at Christies for free - check out Sotheby's too.