This is probably a newbie question (but I am after all a newbie), is it possible to use SharePoint Foundation to personalize the home page of the portal based on the user’s id? For example, if I wanted to keep a task list specific to a user and ensure they could see the list when they logged in, would it be possible?
Yes, this is certainly possible.
One way to do this is to create a "View" with a filter, where the "Assigned To" field is equal to [Me] (including the brackets).
Then, add the Task List to the homepage, and set the view for which it is to use to to that View, and every person who will log in to that page should only see Tasks assigned to them.