I am using Google Translate to register a Russian website. I successfully registered my account but I found that when I use Google Translate, I cannot sign in, and when I don't use Google Translate, I can sign in but I cannot understand what the webpages mean. I wonder if there is a solution.
You can't do that by translating the page through the Google Translate, because you're running inside an iframe, so it's basically works only for public pages that doesn't require login.
Install Google Chrome and visit this page. It will offer you to translate it, or if it's not then right click anywhere on the page then choose to translate this page.
Also you can always translate Russian sites by selecting the right option from the top right corner when using Chrome.