There is nothing wrong with you using the french defense as your opening system, but you sound like you want to solely study the french to get good at chess. Unfortunetly I never judge a player by there online rating. So please tell me what is your chess playing strength before I give any suggestions.
How to make the most out of opening theory/studying?
For many opening books, I think that they are written to be a combination of instruction manual and reference. The idea seems to be that the reader skip much of the reference material and consult it only after playing a game that raises a question addressed by the reference material.
In a 2006 GM John Nunn book, in connection with opening study, it is stated that, if a "book contains illustrative games, it is worth playing these over first", and the reader was also advised, "To begin with, only study the main lines - that will cope with 90% of your games, and you can easily fill in the unusual lines later."
In one of his books about an opening, GM Nigel Davies wrote (2005), "The way I suggest you study this book is to play through the main games once, relatively quickly, and then start playing the variation in actual games. Playing an opening in real games is of vital importance - without this kind of live practice it is impossible to get a 'feel' for the kind of game it leads to. There is time enough later for involvement with the details, after playing your games it is good to look up the line."
"... After each game look up your opening in a book (or database) and answer the question 'If I had to play this opening sequence again, where would I deviate?' In this way you slowly but surely learn opening lines and avoid all major traps. ..." - NM Dan Heisman in his 2010 book, A Guide to Chess Improvement
"... I feel that the main reasons to buy an opening book are to give a good overview of the opening, and to explain general plans and ideas. ..." - GM John Nunn (2006)
"If there isn't any text - if it's all just moves - then this isn't the book for you." - GM Andrew Soltis (2010)

There is nothing wrong with you using the french defense as your opening system, but you sound like you want to solely study the french to get good at chess. Unfortunetly I never judge a player by there online rating. So please tell me what is your chess playing strength before I give any suggestions.
I play around the 16-1700 elo rated in tournament chess if that's any help. I want to study the French to get good at the French, which is a step for me in order to improve my chess skills. Though I have a ton of other books to study chess, like middlegame and such, in order to improve.
Hi! I've recently bought "Play the Frenche!" in order to become very good at that opening. I am now seriously trying to become very good at chess and need help in how I can study this opening with this book. The book contains ALOT of variations and lines!...So how does one use that information to ipmrove and to gain knowledge in the opening? I've have tried to read through some pages (in ebook format), but it is imposible to memorize (even though one should not memorize). Tried to understand the ideas behind the variations.
I've tried Fritz opening training, but i't dosn't work good at all. My own ideas in this topic is that one should analyze every game that he/she has played that opening in, and make comments, suggestions, and start building a own theory bookish contained by this player's own misstakes and experiences. After a finished game, checking with the book and comparing.
Asking my friend to play only the french with me in our corr chess games, I think is a good way to study.
TL;DR How should I use opening books that contains very much variations and sidelines, and very little verbal comments? (In order to improve and learn the opening)