Just lost Mother, now what do we do?

My Mother passed a little unexpectedly about 3 weeks ago. There is no will that we know of, she left myself and siblings as beneficiarys for her 401k, she owned a house (no mortgage), she left no benefiarys for her life insurance. She also has a lot of savings bonds she had been piling up. What happens to everything with out a will? We think she made up a will years ago because my sister and I remember her mentioning it before a surgery she had (about 5 years ago). We will be going through her house to look for it, but what if we can't find it?