Help-Plans Behind The Openings

i finally decided not to study openings in detail and to concentrate on middle game .

can somebody tell me where i can study the strategic plans behind the openings?

The easiest way is to go over annotated games of Masters in classical openings played in the earliest of games and slowly work your way chronologically forward.

You may be tempted to pull the latest Anand or Kramik game but there are far too many nuances for somebody starting out to absorb ... so I'd begin with the older games first => Morphy, Steinitz, Lasker etc. and work my way up through Capa and Fischer. 

The next best thing is for you to get a good book on Pawn Structures ... these investments of study will trump a 100 opening books and really do wonders for your understanding of plans in general.

I'd recommend Kmoch's Pawn Power and/or Soltis and Baburin's more recent works on the theme of pawn structures.

The book of Reuben Fine "Ideas behing the Chess Openings" is interesting.

Watson's "Mastering the Chess Openings" are good for that too.

Why not study openings along with the middlegame plans that arrise from them? They explain to you your whole game plan mostly because opening understanding streches far into the middlegame and sometimes even endgames are considered. Imo to just ignore opening understanding and study middle game is like wanting to learn how to find your way from A to B to C but only learning how to get from C to B and not A to B.

Once you understand the path from A to B you can study annotated GM games and/or skim through games in databases arrising from your opening to see how the game develop.

thanks for your suggestions 

Fine-Idea's Behind the Chess Openings.....Excellent, but out of date.

Watson-Mastering the Chess Openings......Excellent, but doesn't cover all variations.

van der Sterren-Fundamental Chess Openings...Excellent, but lacks depth.

I recommend FCO to decide what you want to play-then buy a specialist book