Try to play over the game in whole to get a general idea. Then you play the game again. If you have trouble with the sidelines, just use two boards. One can have the position after the opening, the other can be for looking at the sidelines. Don't look at the lines randomly, just see ''why the author says it is a clear improvement.'' It is ok if you don't do the whole game: Just understand a few lines.
In time you will get much better at just ''setting up a past position from the top of your head.'' You won't need two boards as much and you won't have to replay the game as much. All of this is much easier with a PGN viewer.
I have personally never used two boards: I am quite happy to play the game over again to the critical point. I mostly don't lose track from looking at one variation either: You can simply play the variation backwards to get back to the stem position too.
Also good books have diagrams.
Hi there,
I have problems with reading chess books. I always get overwhelmed by all those variants. Can't follow the games in my mind so I play it on a board, but after a few variants, and putting the pieces back and forth and back and forth, I mostly lose track of the game. That frustrates me and I put the book back in the shelf - for months until I try again (with the same result). And it's not only books for pros that have so many variants but also books intended for beginners.
So what's the trick? :)