This is directed to newbies in Japanese grammar like me :P.
I have recently found a nice channel on Youtube where Hanako (japanese native speaker) gives grammar lessons live, and for free. You can also ask questions with the chat and she replies!
The appointment is every Saturday PST 3PM, but you can also rewatch the lessons afterwards. There are already 30 episodes posted.
Here is the link: https://goo.gl/iYr4sk
The lessons are organized following Genki I, so it is perfect if you are studying from there.