I can't quite figure out how to join either an Exchange or Round Robi
If you look carefully, you will see that some are marked NEW and some as UPDATES and then there are those that don't fit in to any catagories. Look for one that says NEW like:
NEW: New Year Seed Swap.
Once you find one that says NEW and post your interest, you will be directed by the OP (original poster)on how to proceed.