Organiser: Research a wide range of accommodation in the places you will visit. Be ready to provide recommendations once you meet your group to make decisions. Which factors are the most important for you? Cost? Location? Quality of service? Here are some links that may help you find the information
Designer: Research dining options in the different places. You just need to plan dinner as lunch will always be a sandwich on the spot. Click on these links to get some ideas.
Economist: Keep track of all the costs. It is time that you start writing your budget.