I decided to wait and have my children learn to read and write the community language first in school before teaching them English. My concerns were more learning-based, than practical. I'll explain; the French aren't into positive reinforcement, are much harsher graders and critisize with abandon. I had visions of my commending my children every two seconds and having them basically go through cultural shock when faced with the more grim reality of a French school.
They learned to read and write the two school languages quickly once in the equivalent of 1st grade (French kids are given a lot of pre-reading skills). They're in a bilingual program learning French and German. I was all ready to teach them English... then didn't have to. Yes, they were able to "get it" just by applying what they learned in school, to their spoken English.
Is their English at age level? No but we have no plans to move out of France. I did have to explain some things, i.e. "oo" in pool and cool, the two vowels together, saying the second sound, etc.
I did have English language alphabet books and learning to read toys. This was not confusing to them.
At such a young age, I would urge you to speak Russian, and only Russian to him. Please don't be tempted to slip into English. This will actually help both languages, to keep them separate. I would only approach Russian reading when he shows an interest... and I predict that he will. My kids were naturally curious about how English was written, once they mastered French. You can do subtle things like run your fingers on the letters when you read to him in Russian.
By the way, I don't recommend translating books. My youngest especially was able to identify the French from the English books. These are the ones I read to you but ask Papa to read that. If she really insisted, we could talk about the pictures but not read the text.
My two older ones also take Hebrew. They don't find it confusing and don't mix any of their other three languages lol! We have Hebrew fridge magnets. They play with them and put together words. Try to get a hold of a Russian set!
So don't feel rushed into this project or be afraid of any confusion. Speaking is a skill they have to learn by a certain age but reading and writing have a wider "window". Also, a child's languages, both written and spoken, don't have to both/all be at age level, only the school language, when they are school aged, do.