You could also try NeoOffice, which is also free and based on Open Office. I use NeoOffice and iWork, depending on what I need to do. I don't have Open Office, so can't comment there.
I use iWork when I need to something to look good. I'm a photographer, so visual presentation is important to me. The page layout in iWork does everything I need it to do when I'm working with posters, cards, short documents, letters, ads, etc etc.
If someone sends me a complex word document I will often use NeoOffice to work on it. iWork will work as well, but it just seems more appropriate to use a Word clone when working on a Word document. Its not rational, but there it is...
Congratulations. Welcome to the Mac World.