I guess I'll try to add some random thought's:
Producer = PLC that generates data
Consumer = PLC that reads the data from the producer
The best way to setup communications from the consumer to the producer is to build a path to the producer under the communications card of choice. Then when configuring the consumer tag, you can select the producer controller.
You must set the number of consumers in your producer tag properties. It is 1 by default. If you need more than one consumer viewing the data and you forget to change this, the first one connected wins.
If you choose to make them unicast (there is an option for this when configuring the tags), you need to make them both unicast.
You can only create Produced/Consumed tags offline. You will not have the option online.
Good for you on trying something new.
I'm not sure of you level of understanding on Logix platform, so let me know if I can clear something up.