http://www.theyellowpencil.com/grampasadosimple.html Form, pronunciation and activities.
http://www.youtube.com/watch?v=u66yIqn3MlU&feature=fvw A song by John Lennon to practice the past simple tense (affirmative and negative). You can also find the past continuous tense.
http://engalego.es/almacen/lim/past2/past.html Activities to practice regular and irregular verbs.
Regular verbs
Video about past simple of regular verbs. Rules for affirmative, negative and question forms:
http://www.theyellowpencil.com/gramaregulares.html List of verbs and pronunciation of -ed.
http://www.youtube.com/watch?v=zh_DM7qJGWo Past simple regular verb endings: voiced and unvoiced sounds.
Irregular verbs
http://www.theirregularverbs.com/ All the irregular verbs of the English language: conjugation, pronunciation, translation and examples.
http://www.englishirregularverbs.com/english.html The fastest way to learn the irregular verbs. El enlace ha sido enviado por el profesor Francisco Pineda.
http://www.theyellowpencil.com/gramairregulares.html Grammar rule, pronunciation and activities.