Menu Separator and Drop-down Menu

Hello. I'm currently using the Danland theme and I've centered my main menu across the top (unlike the Danland demo). I'm wondering how to get a menu separator to show up on the left side of the left-most menu item, because as of right now they're only showing up to the right of the items (http://i.imgur.com/NAXpL.png).

#nav li {
float:left;
background:url(images/menu-separator.gif) no-repeat right top;
height:35px;
padding:0 1px 0 0;
}

My second inquiry is how I can go about getting a drop-down menu working for my main menu (where you hover your mouse over the item, and the menu drops down). Is it possible to layout the drop-down menu so it opens up down and horizontally, perhaps into a 3 x 5 grid rather than a 15 x 1 list?

Thanks, and much appreciated.