Subnetting table for C class IP addresses

Finally, a more detailed explanation of Subnetting table for C class

Class C has 254 hosts per network and the total number of networks around 2.097.152

Basic of Subnetting Network and IP addresses

I hope you are able to understand something of this on Subnetting and VLSM if you want to see more RFC 
Btw: These things are taught at CISCO - CCNA academy.