In the past also Russian students used my English teaching services.
I know some sites geared to Russian speakers learning English that could be valuable to them:
englishtips.org; englishmadesimple.com; lingvoforum.net
englishspeak.com; homeenglish.ru;
download-esl.com; engmatrix.com;
ilearnwords.com; supremelearning.com
In addition to these sites, there are a lot of sites on English learning audios and videos.
For Russian speakers there are also the following comprehensive English conversation books:
1. Conversational English (by V. Voitenock, 1999, 480 pages, advanced Colloquial English)
2. The English-Russian Dictionary of Everyday Phrases (by M. Dubrovin, 1993)
3. A Manual of Russian and English Conversation (by Julius Cornet, 2009, 476 pages).