S.C.
S.,
I did this for my husband when he got his BA as well as a retirement party. You say you have the location but have you decided if you will serve alcholic beverages, or will it be dry. Catered or preparing the food yourself? First cover location (done) then menu, then shopping lists if you are providing all the food or meet with the caterer and work on the menu. As mentioned by another poster, you don't really need to plan a program unless you want to, just let people drop in, eat, talk with you and your husband and come and go at their leisure. The key is when you get the big items nailed down is to get to the details. Table coverings, table service, decorations for the tables. To make it run smoothly you need to think of every detail. Do you have a cork screw on hand if you are opening a bottle of wine or champagne. Something as minor as not having serving spoons and a cork screw can throw you into a last minute panic. Take time to think through every aspect of the night, visualize it and make note of all the things you will need when you get to the hall. Even down to walking through the food line and dishing up your meal. So much depends on how much you are doing yourself and what is provided at the place where you are having the event. If there is a full kitchen, that's better yet, if no kitchen be prepared to empty your own of essentionals. Good luck to you, it is a very nice thing you are going for your husband.
S.