If you want to work more your BJJ with a partner, this free e-book can help you. It's always good to train more than just the training. It's always good to do some drills daily.
Personally, i have the chance to have a girlfriend who also train BJJ, and even with a knee injured and the ban to go on the mat until June, i can do some drills, at least to keep in touch with BJJ.
It's nice to read a book who explain to you on a simple way the drills. You can understand what difference between them, what kind of drills do you have to choose to improve your game. This book also offer to you a game analysis grid box for your self evaluation. (Or why not from your teacher or coach ?). But i think it's very good to ask yourself avout the weakness of your game.
Inside you have links for youtube videos about drills, which is an amazing idea, make the thing clearer.
For me the book just has a minor default, it misses a bit of different drills example. Maybe it's just me, but i'm accustom to see pictures to embellish the words.
However it's a cool book, especially fro a free e-book. And thanks to Tom Barlow, the author, to share it for free !
So if you have time, if you want to improve your BJJ and work with drills, just download it ;)