Skype on Windows, Mac, Linux, Web and Skype for Windows 10 (version 14)

1. Select the  New Chat button, and select New Group Chat from the list.
2. Enter a name for your group, which is required to continue.
3. Select the Camera  icon to upload a photo for your group.
4. Select the right arrow  to create your group.
5. Start adding contacts. Select contacts from your suggested list or select Search, and then type the name of the contact you want to add. Continue searching for and adding as many contacts as you wish.
6. Select Done to start chatting. 

Skype for Windows 10 (version 12)

1. Select the  New Chat button, and select New Chat from the list.
2. Choose the contacts you want to start a conversation with. 
3. Select Start to begin chatting. 

Learn more about customizing and managing group chats.