VOB Movie File On Site?

to be able to place a video on a website, but it's in VOB format. There are several files with that extension included with the movie. The movie has an intro where you can choose a from a menu to see various parts of it.

I believe this movie needs to be converted to a diferent format (MPEG3 or 4, or ?) to be used on the site, but haven't done this before. Ideally, I'd like to be able to have it in pieces, so the menu calls separate files allowing it to be downloaded and viewed only if they want that section as opposed to downloading the entire huge movie to see anything at all.

Can this movie be broken into parts as separate movies or clips?

What software can do this (I have Nero, which claims to be able to convert, but has nothign about splitting the movie)?

What format should be used (it's a demo movie for a product)?

I've never worked with movie files of any sort before, so any help you can offer would be most appreciated. Searching the web hasn't produced anything remotely useful, maybe because of incorrect search terms.