How do I make a DVD from a slideshow in IPhotos that will play on my TV/DVD player

1. Export the slideshow from iPhoto using the File -> Export command. This produces a quick time movie of the slideshow.
2. Burn that to DVD using an DVD authoring app. Which one? Depends on what version of the OS you have and how much you want to spend.

BUT... depending on what version of the OS you have, you may need to, or maybe not.

Export the slideshow from iPhoto, that makes a movie of it.

If you have iDVD then that's the app you use. However, iDVD is no longer developed or distributed by Apple. You may be able to get it on an old iLIfe install disk.

Other options:

Burn: http://macupdate.com/app/mac/21992/burn

Toast: http://macupdate.com/app/mac/6351/toast-titanium

But there are lots of others too. Search on the App Store or MacUpdate

If you have an old version of iDVD floating around, it works better if you run it from an external disk.