The basics:
CIDR - "Classless" InterDomain Routing -
This refers to the ability to consider a subnet address with a mask other than what its class defines. So, the address 1.1.1.1 is a class A address, and therefore, would naturally have a mask of 255.0.0.0. CIDR allows you to break up subnets so that you might have a subnet 1.1.1.0 mask 255.255.255.0. A routing protocol that allows CIDR can route between/to these more specific subnets.
Summarization - is just that. So, if I gave you the subnets 10.0.0.0/24, 10.0.1.0/24, you could summarize that to 10.0.0.0/23. That means, if those two subnets are connected to seperate interfaces on your router, say on the "inside," then on your router - you could advertise on the "outside" that you know about 10.0.0.0/23 - this technique helps keep routing tables compact.
Cisco's site can give you the rest, but if you understand the basics as listed above, you're halfway there.
Good day!
Paul
