Ilya Repin is, in my opinion, one the the greatest painters ever...
He was a master of color, composition, theme, expresion and I could go on and on. I have mentioned before and I will probably say again, find the artists that you love and aspire to be, and study and emulate their art. If you can go to the museum and study it and make sketches of their work in person, so much the better.
You can see Ilya's work (and most other artists) at Olga's Gallery online at http://www.abcgallery.com/R/repin/repin.html Very detailed site, a bit rough around the design edges, but great content.