Forms:
http://www.englisch-hilfen.de/en/exercises/tenses/simple_past_ed.htm
http://www.englisch-hilfen.de/en/exercises/tenses/simple_past_ed2.htm
http://www.ego4u.com/en/cram-up/grammar/simple-past/exercises?03
http://www.englisch-hilfen.de/en/exercises/tenses/was_were.htm
http://www.englisch-hilfen.de/en/exercises/tenses/was_not_were_not.htm
Irregular Forms:
http://www.ego4u.com/en/cram-up/grammar/irregular-verbs/exercise?0
http://www.ego4u.com/en/cram-up/grammar/irregular-verbs/exercise?1
http://www.ego4u.com/en/cram-up/grammar/irregular-verbs/exercise?2
http://www.ego4u.com/en/cram-up/grammar/irregular-verbs/exercise?3
http://www.ego4u.com/en/cram-up/grammar/irregular-verbs/exercise?4
http://www.ego4u.com/en/cram-up/grammar/irregular-verbs/exercise?5
Statements:
http://www.englisch-hilfen.de/en/exercises/tenses/simple_past_statements.htm
http://www.englisch-hilfen.de/en/exercises/tenses/simple_past_statements2.htm
http://www.ego4u.com/en/cram-up/grammar/simple-past/exercises?04
Negations:
http://www.englisch-hilfen.de/en/exercises/tenses/simple_past_negation_sentences.htm
http://www.englisch-hilfen.de/en/exercises/tenses/simple_past_negation_sentences2.htm
http://www.englisch-hilfen.de/en/exercises/tenses/simple_past_negation_sentences3.htm
http://www.ego4u.com/en/cram-up/grammar/simple-past/exercises?05
Questions:
http://www.englisch-hilfen.de/en/exercises/questions/simple_past.htm
http://www.englisch-hilfen.de/en/exercises/questions/simple_past2.htm
http://www.ego4u.com/en/cram-up/grammar/simple-past/exercises?02
http://www.ego4u.com/en/cram-up/grammar/simple-past/exercises?06
http://www.ego4u.com/en/cram-up/grammar/simple-past/exercises?07
Mix:
http://www.ego4u.com/en/cram-up/grammar/simple-past/exercises
http://www.ego4u.com/en/cram-up/grammar/simple-past/goldilocks
http://www.ego4u.com/en/cram-up/grammar/simple-past/goldilocks?02
http://www.ego4u.com/en/cram-up/grammar/simple-past/goldilocks?03
http://www.ego4u.com/en/cram-up/tests/simple-past-1
http://www.ego4u.com/en/cram-up/tests/simple-past-2
http://www.ego4u.com/en/cram-up/tests/simple-past-3
Pronunciation:
http://www.englisch-hilfen.de/en/exercises/pronunciation1/index.php