Another tip for Janie, when trying to open files on Macs with no separated left & right buttons on mice;
Single clicking works on hyperlinks while double clicking is required for files and aliases ("Shortcuts" on Windoze).

Trying to open a file when not in an application will usually open the file unless something doesn't get recognised as a file of a particular type. Macs will then usually give a dialogue box asking you to choose an application. I've not used iWorks but I suspect it is capable of opening most file types

When you're in iWorks and wish to open a Word (or other) file from within the iWorks application, Cmd O should give you a series of option similar to the dialogue box method mentioned above.

Cheers, Rowan