How can I manage a users collection of products? I am pretty new to Drupal, and I am tasked with creating a Drupal 7 site that has a lot of products; I need to enable users to maintain a list of the products that they own/have.  

Basically I need the ability to take a list of products and allow a user to check off the ones they have and the ability to save this data associated with the user. Is there a module that I should take a look at, or can someone point me in the right direction?
Check out the Flag module.  You could create a product content type and then your users could flag which individual products they have.