Newcomers may prefer to start at the top with the Impressionists and Post- Renoir, Cezanne, Manet, Monet, Toulouse-Lautrec, Degas, and Van Gogh (this is the best collection of his work outside Amsterdam, with several works from the frenzied months of activity before he died in 1890).
Newcomers might want to stop with Impressionists.