After an emergency many people want to donate to the response/relief efforts.
The best way to donate is to contact already established relief organizations such as the American Red Cross or the Salvation Army. A full listing of volunteer organizations active in disasters in Washington can be found here.
When thinking about donating, the best type of donations is monetary. Below are a couple videos explaining why monetary donations are preferred. If you have items that you wish to donate, you can hold a yard sale for those items then donate the proceeds from the yard sale.
If you would like to donate food or unopened hygiene items you can contact your local Food Bank.
Alternatively, you can contact your local fire department (after an incident is over) and talk to them about how you can donate to their organization.