“The hard part first” is a post I came across via Designer Depot. Now, there’s not research into it but as soon as you read it it makes complete sense. Basically, what Chris Coyier proposes is that when doing form design, we should put the actual action that the user requested first.

This might sound obvious at first and you might not know what the hell I’m talking about but think about the form for leaving a comment on certain websites. First thing you’ll get requested for are your details, and then you can leave a comment or send a message. We’ve been doing it like that for so long that we haven’t even questioned the way it works. What Chris suggests is that we put the actual comment box first and then we go into the annoying details which make the process more cumbersome. That way you commit to filling the form and, for whatever the reason, it seems like an easier experience.

Anyway, he has more examples in hist post so take a look.