For a live demo of O2C cycle, you can take an instance of many E-Commerce businesses. For instance if we take the example of Dell..As a user you go to dell.com and search for a laptop and order it(This is the booking stage). dell.com processes your order and tries to pick release it by checking the inventory, if they have on-hand quantity for the item you ordered, it's pick released and shipped providing you a shipment date and the tracking#, you would be invoiced for the item you ordered(invoice & receipt-upon your payment). If you happen to return this item then a credit memo is created. At the end of month or quarter dell.com has to analyze the sales and finances for that they post it to GL.
For functional flow or technical flow you can always google where you get lot of results.
Hope this helps!
Visit the following links. May be useful to you.