Any reasonably-sized reference library should have a copy of 'English Surnames' by Reaney & Wilson (or a similar reference work). There are also plenty of people on this site (including me) who've got a copy of that book on their bookshelves. So, if you don't mind revealing your surname to us, someone here might be able to help you.
Thanks. Really interesting. I was disappointed that it didn't say something along the lines of any Milham is a direct descendant of some King and has millions of pounds waiting to be collected. Just ordinary people from Norfolk apparently. :o)