Find out how many are going to be in your group. You should have a confirmed number of travelers before you try to find discounted rates on bus tickets. Companies may give you a different rate based on the number in your group.
Pick travel dates and your destination. The time that you plan to travel and the destination is additional information that you need prior to looking for bus discounts for your group.
Book a bus tour through a travel company. The easiest way to get a group discount is to contact a travel agency that arranges bus tours. You can search the yellow pages for local companies or go online to a site like Riley's Bus Tours.
Contact a bus company directly. If you are just looking for bus tickets, then simply contact a bus company to see about group rates. You can try Greyhound first to see about their group rates.
See if you are eligible for senior group bus ticket rates as well. If you have numerous seniors in your group, you may also be eligible for a senior discount.