Hi,
Serialization / Deserialization can be tricky at first. The best way is to rely on examples and built-in functionalities.
Have you checked "src/internet/model/ipv4-packet-info-tag.cc" ? It could provide a very good guideline for what you need.
About a thing to study... other than pointing to the manual I wouldn't know how to help you. If you have specific questions, ask them here and we'll try to enlighten. If there's a manual section that seems to be obscure, let us know and we'll try to clarify it.
Cheers,
T.