VOB files are a bear to edit. Plenty of programs will promise to handle them, but never work right (I've had several programs get perpetually stuck loading the file for instance) or you'll get massive sync problems when you change formats.
Best luck I've had is with Womble's Mpeg Video Wizard (wombledotcom). It's small, runs in real time, very easy to use, and you can download a trial version that's fully functional for a month (and you can redownload and reinstall it pretty much as many times as you like---they don't do anything to prevent that, as I well know, though I did eventually buy it). It's a good solid editor and you have a lot of compression choices for output, plus I've never had it lose sync. The only slight problem is that sometimes it gets tweeky when handling non-mpeg formats, particularly if a file is really large. It also is somewhat limited in types of file output it will do (basically it's meant for mpeg and dvd). However, when I need to go to a format it doesn't handle, I just create an mpeg, then use a converter. For some reason, I haven't had problems doing it that way whereas I have going straight from DVD.
The other program I've worked with that handled VOBs fairly smoothly is Adobe Premier Elements. It's a pretty good program overall, but rather large and overloaded with bells and whistles. It does have the advantage of handling alternative file formats a bit more easily and being a one stop shop for multitudes of output formats, but it can also be rather overwhelming and the learning curve is a bit steep if you've never worked with this kind of software before.
The only other option I can think of is if you can find something that will reliably do your conversions to another file format, use DVDShrink (freeware--don't have a link to it on hand though) to do the cutting, then convert, but you'll probably also need a program to link files into one file (I know there are several freewares out there that will do it, but I don't know what) as I believe DVDShrink turns the cuts into separate files. Problem there is you'll need to bounce from program to program, but you can probably do it totally with freeware that way way, whereas Adobe Premier is about $100 just to try and Womble, while you can use it for free, does cost about $100 if you wind up paying for it.
Good luck.