Your agent will work with the escrow company selecting during the offer process to official open the account. The escrow company will then contact you directly (or via your agent) to provide you with the details to deposit the earnest money into the account. You usually have 3 days to make this happen. The sooner the better to keep the process moving.
A good escrow company will package forms together and send them all at once versus sending you documents multiple times. You will receive a first escrow package that will include tons of information and a variety of documents such as seller's and agent disclosure (this may come later), some history about the property, various disclosures for the property and even HOA documents.