Russian visas can only be obtained from Russian diplomatic missions (embassies or consulates) or, increasingly, from licensed Russian visa centers to which visa services have been outsourced. If you do not live near a major city, then attending a consular department or visa center in person may be difficult, and you may prefer to apply for your visa by post if you have the time or opportunity, or use a local travel agency offering paid Russian visa services.
To find the address and contact details of the nearest Russian consular department or visa center, check the website of the Russian Ministry of Foreign Affairs here.