Personally, for the sites I have worked on and used, I like to have the page load input focus of a page that is primarily a form have set to the first box, e.g. 'your name'.
I believe that the internet is 'all about speed' and I consider 'Contact Us' to be the second most important page on some websites, therefore I want to get it right. To me contact us forms that don't handle the pageload focus are inconsiderate and unfinished.
Earlier on another SE, after suggesting setting the input focus I get told that:
Modifying the normal behavior of a web page/browser is typically seen as a universal usability no-no. It's also big accessibility problem. If I were to load your form, my screen reader would start reading "Form, First Name". A user may want to read the title of the page. Or intro paragraph first. If they want to jump to the form, they can.
I now would like to know what is best practice and how to build my form so as to account for screen readers, e.g. some check in my script to set the focus only if a known browser is used.