food is a great idea. My mom passes last year. You don't really feel like cooking, you just feel crappy. So having some gift cards to a local place to eat, or delivery place, or even sending over food is great. Food is a great choice, but you might want to make sure no one has a food allergy, or restrictions of some sort.
Someone mentioned something about father's day. You could always send a card and something small now. I will say about after a few weeks, or a month people tend to forget that you are still grieving for the loss of your parent. So, father's day is going to be really rough this year. Maybe send a card then. You know, let them know how sorry you are about the loss, and still thinking about him and his brother.
In the next few months taking time to call and talk, will mean a lot.