Pick a date. Especially if you live in an area that has multiple colleges all getting out for the summer around the same time, you may need to reserve the van early to ensure you can get one for moving day.
Make a list of any large items that you will be moving and approximate the number of boxes you will have. Decide if a van will be large enough to move all of your stuff or if you will need to rent a truck. Most rental companies can help you decide how much space you will need. For the average size dorm room contents a van is usually large enough.
Decide if there is anything else you might need to rent for moving day. Most rental companies also rent dollies if you will be moving anything that is too heavy to carry.
Check your local phone book for a listing of area car and truck rental companies. Make some phone calls to see who has a van available for your moving day and how much they will charge you for the rental.
Shop around to determine who you want to rent from and reserve your van. You will need a credit card to reserve and rent a van.
Line up friends to help you move your stuff out of the dorm. If you can't find help and will be moving yourself, be careful not to pack any boxes heavier than you can easily carry.