@wifeysays I will guess your iMac is only a year or so old. Does it have iWork as an application?
This can be found out by opening up “Finder” and looking in the “Application” list under devices and look for a folder called “iWorks” inside “Applications.”
If you have iWorks you can use the the usb and connect to the iMac and open up the .doc files.
Or use @YoBob ‘s link to get OpenOffice do the same, connect the usb and open up the.doc file.