Where can I find documentation about interacting with bitcoind's json-rpc? I have created a coin by forking Bitcoin. Now I want to create web wallet for this, but do not know how to create json-rpc apis to communicate with the daemon server.
Is there any proper documentation for this?
Visit API reference (JSON-RPC)

There are several solutions:


You can build bitcoin-cli (which provides json-rpc communication with deamon through command line), and call bash commands on the server. For example, if You run PHP server, You can asynchronously run bash commands.
Also You can use json-rpc libraries on your server - feel free to google for them. For example, if You run PHP server, You can use a library like php-bitcoin-api.
Also, I recommend You to run own blockchain explorer which will help You to communicate with a blockchain of Your coin. For example, try to run bitcoin-abe explorer or any other.


Hope it will be helpful!