Hi.
Google Protocol buffers are good for serialization
some advice:
1: learn how to use a network to establish a connection between two applications.[It is recommended to use TCP]
2:how to transfer a message(safety) between server and client;[ yes, u can use Google Protocol buffers , its a good choose]
3:now you can deal with your agreement, such as pick up item or use a skill;
4:them, u can do some to save data and load data when player online.
there have a opensource solution written by me,it contains those I said above.https://github.com/ketoo/NoahGameFrame
https://github.com/ketoo/NoahGameFrame [A fast, scalable, distributed game server framework for C++]