I can read, but not understand, Russian, but right there on the home page there's a picture of two masks with a link that says "Пурим" (which transliterates to "Purim").
Also, JudaisminRussian.com (a division of Friends of Refugees of Eastern Europe (FREE)).
For print materials, I know Kehos has good outreach materials in Russian, they're in use in Chabad Houses the world over, especially Russia.
I'd say most, but not all, of the Russian books there are at an introductory level, so that's something to think about. But here's the Complete Story of Purim in Russian.