This really is a bit much for someone to explain on a forum. There are techniques to achieve each effect you have going on.
For instace the rounded containers you would slice the top an bottom off so you've got all the way until the curve has reach the full width and you would place them above and below a wrapper with the same width and backg round colour.
As for the rolloever effects, you need to look into CSS :hover effects. If you are trying to get the background to move to the link of the current page then you just need to add an ID to the current link and reference it with CSS telling it the background it needs to have.