First there is a nomination stage where you suggest pairings you'd like available, by adding them to the tagset on AO3.
Then there is a signup stage, and once that's open there will be a sign up option on AO3, but that's only going to be available after 15 June.
When you sign up you include details of what you are willing to write (your offers), and your prompt etc for what you would like written for you (Your requests).
The people running it will then match people up so they find a match for someone offering to write fic for one of your requests, and they will send you details of your assignment. There is a place on your AO3 dashboard which shows you your assignments.
Then you write your fic and upload it to the AO3 collection for the exchange.
Re: Bangs, fests, exchanges etc - ALL CAPS Exchange
Then there is a signup stage, and once that's open there will be a sign up option on AO3, but that's only going to be available after 15 June.
When you sign up you include details of what you are willing to write (your offers), and your prompt etc for what you would like written for you (Your requests).
The people running it will then match people up so they find a match for someone offering to write fic for one of your requests, and they will send you details of your assignment. There is a place on your AO3 dashboard which shows you your assignments.
Then you write your fic and upload it to the AO3 collection for the exchange.