Sorry I can't explain this easily with words, so I got some screen captures to help. I want to do something on my site similar to the AdWords help block that sits towards the top of the page but when you scroll down it stays at the top.
Eg, when looking at the top of the page:
Now, I have scrolled down the page, the help section stays "docked" at the top:
I'm wanting to dock a form like this, in the left column, that is contained in a div with id="leadsbox".