This should help you… Then all you need to is to remove the Add to Cart button stuff from template.
p.s. Not sure if this Mage_Checkout set to disabled turns Add to Cart by itself…
Old post with useful suggestion, so I think I would update the information: on Magento 1.3 you need to manually remove the “Add to Cart” button, which still appears after disabling the module (leads to empty page).
The exact code to remove and edited files are explained in a few discussions around this forum.