I've made a couple raffle quilts for the Alzheimer's Association. After you contact the organization to let them know what you are planning they will be happy. Some thoughts that might help you: Are there quilt shops/other businesses in your area who may be willing to put the quilt on display and sell tickets for you? You could move the quilt around to different businesses depending on your time frame. The non-profit may be able to get an article in the paper to let people know where the quilt is on display, how the money is helping their organization, ticket price, etc. Business owners like this. I got permission from a local grocery store(s) to sit outside with a table, the quilt, handouts from the Alz. Assoc. and it was a so-so sucees from a fundraising standpoint but helped raise awareness.
If you decide to make the quilt remember that nothing is perfect and it will be beautiful!!! Us quilters have a more critical eye of our own work than others do. Some will buy tickets simply to support the organization.