3rd Gen What's The Difference?

I reently remembered how i play Pokemon (yellow) on my (now broken) Game Boy Advance, and now a have a PSP and started to play a new versions, BUT a cant get it, What's the difference between, for example, FireRed and LeafGreen, where can i get full list of differences, and i see its many remakes, now i'm playing Emerald and FireRed, and want 2 know, in which capter i must play first second. I see FireRed is remake of yelow\bue\green.
If u dont understand smth, plz, ask

I don't quit get what you mean in some parts of your post ... The difference between FireRed and LeafGreen is that on FireRed you can get some pokemon that you can't get on LeafGreen vice verser, Besides that I don't think that their are any main differences ...

mmm, ok ..
now how many capters of pokemon there are?
But, i mean chapters by storyline, i see R,G,B we play by Ash , But in emerald we play by ???
in R,G,B we fight with team R and in emerald its is team aqua, so there is some any chapters with different stiryline
sorry 4 my bad ensglish, but i cant explain exactly what i want, on language that's different than mine

In emerald you can either choose from Brendan or May.

yep, i know that, In what order i must play pokemon games.?

No order. There is virtually no overlap in story between the games. You can play the games in any order and they will make sense. It might be "best" to play one of R/B/Y/FireRed/LeafGreen first, followed by one of Gold/Silver/Crystal, followed by one of Ruby/Sapphire/Emerald, etc. You don't have to, though.

No order is needed, You don't need to play FireRed for example to play Emerald and understand it ... Play in whatever order you want to, and it's okay your English isn't that bad.