Read the wiki to have a general overview of what Souliss does, the most important are Your First Upload and Getting Started.

Start from an Arduino Ethernet, an Arduino with official Ethernet Shield or ENC28J60 Ethernet Shield. The Hello World example is the right one to start with, use SoulissApp to control your board and turn ON and OFF an LED.

Read carefully how setup the board.

Once you get the Hello World working, is time to define a network of nodes. Have a look to the supported Hardware Boards and start your design.

You can mix Ethernet, Wireless and RS485 communication as you like.