I tried to read this a couple of months ago, but I barely passed page 100. I was totally lost at that point and decided to give up this time. I'd like to try reading this novel again, but how should I approach? Also those of you who read this, what did you think about it? How did you manage to finish reading it?

I think it depends what books you normally read I imagine if you read modern novels then it will seem quite difficult. I found that myself with the great volume amount of characters - especially hard to keep track of as some disappear for about 200 pages before reappearing.
I got half way through and stopped but i'm going to take it up again. I did enjoy it, but it was quite a heavy read in moments.

I read a few lengthy classic novels like ...

Count of Monte Cristo
Les Misérables and
Crime and Punishment.

But I find it much more difficult to read War and Peace than any of these novels ...

I did manage to finish it, after about three years. The problem with it is that it is exciting and mind-numbingly tedious in equal amounts throughout the book. So, you read a really good bit and then you hit a really slow bit and you lose it, and then you have to start all over again.

I'm finding Anna Karenina a much more engaging book

It's on myself waiting for me... I started Tolstoy's AK but never finished it (It needs to be on myself waiting for me!) but lately I've found that I like Dostoevsky (How did you like C&P by the way?) more than Tolstoy, or at least so that, I'd much rather concentrate my efforts into reading the former, rather than the latter. If that made sense.

I also have the book war and peace.
I tried to read but I've not finished the first 50 pages.
Cause I think I'm not familiar with that peirod of history.

I'd rather pick a interesting one.