Hi , I'm new here and this is my first question - hopefully in the right section

I have a few ebooks on my ipod touch but generally don't read ebooks - but do want to publish one .
I have a mac laptop and tried a few tests with textedit which does give the option to save as a .doc file [ I have been advised to get microsoft Word onto my pc and use that rather ] .
My book would involve a lot of images [ photography related ] and I can insert or attach an image in textedit but then it will only allow the option of saving as "rich text with attachments" which is a .rtfd file.
At the moment my head is still spinning with all the advice I received on the local photography forum and I was directed here by one of the members.
So I suppose my main question will be what software to write the book with if I use a Mac [ without getting too complicated ] or do I just work on my pc and get Word ?
Thanks in advance - Desmond.