We were married for three years and separated for the last six months, how do we get divorced?

My husband and I have been married for over 3 years. For the last 6 months we are separated and don't live together. We both agreed that its time to file for divorce. We don't have any kids. This is a first marriage for both of us. We don't have any mutual assets. Whats the easiest and quickest way for us to get divorced? We found out that if both parties agreed on the same decision we can file a joined petition. How's the deal with it? What if our both annual income might be over $35,000? Please give me some information on what's the best way to get it done. Preferably something quick and less stressful. Thanks in advance.