hello
how can i easily see the list of most downloaded books ? once i sign in i cant find the list anymore
thank you

You are using the Classic version of Mobilism, and the footer is only available in 2.0, which is the board style that you see while offline. To switch from Classic to 2.0 go here: http://forum.mobilism.org/ucp.php?i=165

hello
how can i easily see the list of most downloaded books ?

I do not think there is no option to see the "most downloaded" book(s).
However, you can, after doing what merry60 said, see the most "viewed" book(s), which might mean the same thing as the most "downloaded". Check image below: