I have just purchased an i pad some books I wish to download are not listed in i books; so I downloaded kindle/amazon to widen my choice. If I find what I want who will bill me apple or kindle?

If you want to buy ebooks from Amazon then you will need to create an account with Amazon and you will pay directly to Amazon for those purchases - you can't use your iTunes account or iTunes gift cards to purchase from them. Also you will need the Kindle app on your iPad to read Amazon's kindle ebooks - ebooks tend to have digital rights management on them which tie them to the store's own apps and ereaders, so Kindle books can only be read in Kindle apps/ereaders, and ibooks from Apple in the iBooks app.

Kindle for iPad help.

You do use the cable that came with the iPad (the same as you use to connect to the wall charger) to copy photos from it to a computer (copying photos) - not sure whether that also has a minimum requirement of OS X 10.5.8 or whether that just applies to syncing. Try taking a photo and see if it your Mac recognises it when you attach the iPad to it - hopefully it will appear as a 'camera' in iPhoto, Aperture and/or Image Capture.