The following words of wisdom come from Tamara Turcott, of An Eye for Detail, who was widowed six years ago. She posted it on a message board used by members of the National Association of Professional Organizers, in response to a question posed there, and I thought this was so good I wanted to share it. Tamara graciously gave me permission to do so. Much of this advice would apply to organizing after the death of any loved one.
Everything you feel and do is OK. If you feel like you can sort through papers, do it. If you bag up clothes and they just can't leave the house yet, do it. I lived with his toothbrush in my cup holder for a year. I cleared out the closet for myself one week before year six. I gave away his walker in the first month. You'll find the items he loved the most, the hardest to part with.
And in the beginning, moving anything feels like acknowledging the loss. I found it easiest to start by giving his belongings to good causes, people in immediate need, and family members who would cherish them. Each gift was a gift from him, and therefore it felt right.
To this day, a pair of destroyed sneakers still sit in my basement because I can't bear to put them in the trash: the only place they belong. There are no rules in grieving except that you are comfortable. The same applies to organizing in grief. You can't know how you will feel until you try, but the second you try, you'll know. Hold the items. Imagine yourself taking the next step. How does that feel? If it feels OK, then do it. If it feels like your chest is tightening and you can't breathe, put it right back down. You will get there. Just not yet.