You can use
Neo Office for your standard MS Office functions. It's free and works very well and presents pretty much no learning curve to someone familiar with Office.
As far as Publisher, MS doesn't make a version of that software for the Mac platform. (I'm surprised your teachers aren't making you use Quark or InDesign since those are the industry standard). I've seen people talking about various alternatives to MS Publisher on the Mac such as Create, Ragtime Solo, Canvas, Pages, Desktop Publisher Pro and of course InDesign and QuarkXpress, but none of them are probably what you are looking for.
That said, XP runs great with Parallels from within OS X and should run Publisher just fine for you. If you already have a computer running XP, then you probably already have an install disc and license key that you can use to install XP inside Parallels and then install Publisher so you can use it without having to reboot.
jag