To highlight menu item corresponding to current page, you might find
this technique  interesting.
In your DW templates, you juste have to specify the ID attribute of the
body tag as editable
If you are working with DWMX2004 the [modify/templates/make attribute
editable] function should do the trick.
Regarding (nested) list styling, here is _THE_ listamatic resource 
Trish Meyer wrote:
QUESTION: My question is with how to indicate to the reader where they
are when they move around the site.
Does anyone have a tutorial they could point me to on nested lists and
controlling their styling from CSS? I find nested lists confusing.
List wiki/FAQ -- http://css-discuss.incutio.com/
Supported by evolt.org -- http://www.evolt.org/help_support_evolt/