Each "sealed bid" transaction will vary depending on the seller(or their attorney or broker) whomever is handling the transaction. Basically if you purchasing a property through this, you will be allowed to view the property during open house times determined by the sellers representative or you can haver your agent schedule an appt, for you to view before the bid begins. If after viewing the property, you are still interested, there will be a package that you will have to submit during the "sealed bid period". Usually you will have to also provide a deposit, which is then returned to you, if you are not the winning bidder. If you are the winning bidder, your deposit will be put in escrow until the closing. The sellers usually accept all the offer that meets their criteria, "highest and best offer". You should verify that you are qualified to bid, some bids are CASH only, while other can be financed.
If you are not working with an agent, please consider doing so, you do not pay a fee in NY, unless otherwise agreed to.
High bid is sometimes determined by the seller HUD for example) as the one which gives the seller the most cash after ALL expenses. Since closing cost cannot be determined accurately at bid closing time offering to pay all closing cost (minus sellers attorney's fees) may make your bid more attractive to a seller than one which has a higher opening amount.