Just some extra stuff to help learn Russian alongside duolingo. Feel free to add.
When I first started learning this language, I was incredibly confused. It's hard to pick it up with Duolingo alone if you're unfamiliar with Russian Cyrillic and keyboard. Same goes for the grammatical rules. So I thought I would share some of the sites I've been using alongside duolingo to help. If anyone else would like to add to this forum, that would be great.
http://www.keybr.com/ This site will help you get more accustomed to the Russian keyboard. It'll make lessons far easier after using it for a while. (It's also wonderful for other languages and people just learning to type)
http://slav.su.se/ryska-tangenter/index.html This was also helpful in learning the russian keyboard. It's in Swedish, but you'll get the basic idea when you see it. Not as good as Keybr but is more like a game.
Memrise.com This site was a LIFESAVER in helping me learn Russian Cyrillic. After using this for a little while, I found it much easier to understand the Duolingo lessons because I could actually recognize the letters. I now do lessons on both duolingo and it. =) I find they compliment each other well.
http://www.russianlessons.net/ I've just found this site. It has grammatical rules, pronunciation videos, and other lessons. It even has a video about the handwriting for Cyrillic.
I know it's a lot, but all together, it's been a big help.
The best (and free) Russian Course is in this Youtube Playlist.
170 videos with the excellent teacher Vera Polyakova Norwood.
There is a textbook with this course with exercises, you can find it to download in some of the comments.
I strongly suggest you to do the exercises with pen and paper, not in a keyboard. The course is from the 90's recorded is VHS, so the image quality is NOT HD, but is the best course available (just read the comments in each video!)
i mostly use youtube videos, both for vocaulary and grammar. Oh and i made fallout 4 russian, i don't understand much but the more i get exposed. =)