I have a draft post about making a will, this one is better than what I can put together.
You can also find a comprehensive checklist for estate planning here.
You can also designate at Medical Power of Attorney, someone to make medical decisions for you if you are unable to make those decisions. There may be one particular person you trust to make these types of decisions, or a person you feel more comfortable discussing your wishes for various medical situations. For more info and sample form, review this page by the Texas Medical Association.