Your options (may be incomplete):
1) Install OpenOffice.org. It opens and saves MS Office documents in principle but chances are it may not open your documents correctly. You can always test with the Windows version of OpenOffice.org first. If it is okay on Windows, it is most likely okay on Linux. Do install the latest version 2.x but not 1.x.

2) Use some emulation software like VMWare or Xen and run your Windows and MS Office in it. I have no experience with this.

3) Run MS Office with Wine. Not necessarily work either.

I believe you can dig out some information by searching for "run MS Office on Linux" from Google.