There is no "going rate" or average rate of commission. The best way to find out is to interview several agents and ask them questions. Don't get too fixated on the amount of commission but rather the services that you will receive.
Not sure what the market is doing in your area, but you local agent should be able to tell you that in addition to giving you a comparable market analysis including actives, solds, expireds. This will give you a pretty good indication of your local market.
In addition, you will want an expert opinion on staging your home and letting you know the types of things that can be done in advance to put your home at the top. It is also wise to obtain a pre-inspection so that you limit the amount of items that a buyer may try to use to bring down the agreed upon purchase price.
Good luck on the sale of your home.