(this page is under construction at the moment)

IANA 

• Port Numbers Registry
• Protocol Numbers Registry
• HTTP Status Code
• IPv4 Address Space
• IPv4 Special Purpose Addresses
• MIME Content Type

Wikipedia

Introduction

• Internet

Application Layer

• DNS
• HTTP

Transport Layer

• TCP
• UDP

Network Layer

• ICMP
• IPv4
• Subnet
• Classful Network
• Classless Network
• CIDR Notation