best way to categorize things?

using the 2011 theme, i am looking for the best way to have a page that then has things broken into categories, such as country/state, also would be nice if i could sort based on a date field. for example an events page that shows items by location, and then by date, or view all by date etc… is this possible, plugin, already way to do this, etc..?

thank you. im just now trying to learn wordpress.