You can install VMware and run a Windows virtual machine and run office in that .... I've got Office installed on mine. Microsoft of course also publish a Mac native version of Office.... hasn't quite got all the cutting-edge bells and whistles of the Windows version, but its got more than enough to satisfy most people.
I use Parallels to run Windows on my MacBook Pro. Parallels is not free like VMware, but I prefer it. I also have Windows on a Bootcamp partition to cater for some programs which won't run in Parallels.
Concerning Office for Mac, I found it very disappointing. In an effort to make it more "Mac-like", Microsoft have produced a menu structure that is so radically different from the Windows version as to be nearly impossible to use, if you try to use both versions.
I am required to use Windows at work, so at home, the easiest solution for me, is Office for Windows running under Parallels.