Protection Paladin Stats.

I play on Icecrown, WotLK 3.3.5

Hello I would like to ask some questions about prot paladin stats.

I've seen BiS Protection Paladins, They were getting as much "Parry Rating" as possible.

Why were they getting as much "Parry Rating" as possible?
What's the difference between Parry Rating and Dodge Rating?

Can you tell me what stats give me:

1 strenght - How much "Block Value" and "Atack Power" I get for 1 strenght?
1 Agility - How much "Critical hit chance and "Armor" I get for 1 agility? Do I get "Dodge rating" ?

What are the caps I need to get as Protection Paladin ?

You need to post this on paladin section of forum bro http://forum.warmane.com/forumdisplay.php?f=120
but hopefully one of forum moderators will see this and move it for you.