Need help with serialization

Im having the same problem for a week now and i dont really make any progress, its the following :
I have an item class and i want to sync the items in the players inventory to other clients and the host.
Do i need to write my own serialization?
OnSerialize(NetworkWriter writer, bool forceAll) {
this.int = .... ;
}
Or is there an easier way ? Like syncing to the server with a command and syncing the clients with client rpcs?
Where would i put my serialization? In the inventory or the Item Script ?
Im really out of ideas can somebody help here?
thx in advance and sry or bad english