OK You just an empty <li></li> tag if you want to use a space but be sure it's list-style-type property is set to 'none'
you don't need a div with in a <ul> I don't understand why you want it? Explain...
<ul> = UNORDERED LIST, this element is used for making lists... i would use soley <div's> only to make the page you have tried to make.
That's just me though...