Used to/be used to/get used to

Here's a link to the British Council's learners' web:
http://learnenglish.britishcouncil.org/en/grammar-reference/used-infinitive-and-beget-used

This one is also nice and clear:
http://speakspeak.com/resources/english-grammar-rules/various-grammar-rules/be-used-to-get-used-to-used-to