Subject + used to + infinitive is used to refer to things in the past which are no longer true. It can refer to repeated actions or to a state or situation.

Subject+ would + infinitive is used only for repeated actions, not for a state or situation.

http://learnenglish.britishcouncil.org/en/quick-grammar/past-habit-used-towouldpast-simple http://dictionary.cambridge.org/grammar/british-grammar/past/used-to

• used to + infinitive refers to actions and situations in the past which no longer happen or are no longer true.
• be used to + noun/pronoun/gerund means 'be accustomed to' or 'be familiar with'.
• get/become used to + noun/pronoun/gerund means 'become accustomed to' or 'become familiar with'.

http://learnenglish.britishcouncil.org/en/quick-grammar/used-infinitive-and-beget-used http://dictionary.cambridge.org/grammar/british-grammar/past/used-to

Subject + used to + infinitive is used to refer to things in the past which are no longer true. It can refer to repeated actions or to a state or situation.

Negative form

• Subject + didn't use to + infinitive
• Subject + never used to + infinitive
• Subject + used not to + infinitive

Question form

• Did + subject + use to + infinitive?

Would is used

• in the second and thid conditional,
• for the future in the past,
• in reported speech,
• for repetition in the past, and
• for polite requests.

http://www.bbc.co.uk/learningenglish/english/course/upper-intermediate/unit-4/session-1