Our thoughts and prayers go out to those affected by the terrible tornado in Oklahoma. I'm sure that ham radio operators and Skywarn members are doing their best to help out in the terrible situation there. If you would like to donate to help out, I found the following news article that lists several charities and support organizations:
I hate having to mention it, but beware of scams when donating. It seems that the scum of humanity comes out to prey on the good intentions of others during times like this, so carefully vet the charity that you are planning on donating to.
Not that anything could ever help if you are in the direct line of fire from an EF5 tornado, but being prepared for a disaster may give you that razor thin edge needed to survive.
If you are in a disaster prone area (I live in Central Florida, where we got four hurricanes in one year's time back in 2004), stock up on food, water, medical supplies, and anything else that you need on a daily basis. Consider joining Skywarn, ARES, or RACES as they supply training in how to prepare and how to cope and even be helpful to others in the event of an actual disaster. You can also go to FEMA's website and take free online training to learn how to integrate into SAR teams and work effectively with local firefighters and police if you are inclined to help others during an emergency.
This goes beyond the technical assistance that most hams think of in terms of assisting with emergency communications. While that is definitely needed, you also need to know how to dig through debris with other teams to find survivors in a coordinated manner so that you can be as quick and efficient as possible. Time is Life in this type of situation!
Again, my family and I will be praying hard for those impacted by this horrific storm. We are not directly involved in any way, but we are still devastated by the loss of life, particularly that of children. We cried our eyes out last night when we heard. Our sympathies go out to everyone involved!