Conditionals: zero, first, second and third type conditionals

GRAMMAR EXPLANATION
http://www.ego4u.com/en/cram-up/grammar/conditional-sentences
http://www.shertonenglish.com/resources/es/conditionals.php with exercises
http://www.slideshare.net/rosarioa.slide/conditional-sentences

Type 0.
http://www.englishgrammarsecrets.com/type0/menu.php
http://www.fed.cuhk.edu.hk/~etenet/SConditionalSentences1.htm

Type 1.
http://www.saberingles.com.ar/curso/lesson19/05.html
http://www.englisch-hilfen.de/en/exercises/if_clauses/type_1_statements.htm
http://www.englisch-hilfen.de/en/exercises/if_clauses/type_1_mix2.htm

Type 2. 
http://web2.uvcs.uvic.ca/elc/studyzone/410/grammar/2cond.htm
http://www.englisch-hilfen.de/en/exercises/if_clauses/type_2_statements.htm
http://www.ego4u.com/en/cram-up/grammar/conditional-sentences/type-2/exercises
http://www.englishexercises.org/makeagame/viewgame.asp?id=5819

Type 3. 
http://web2.uvcs.uvic.ca/elc/studyzone/410/grammar/3cond.htm
http://www.englisch-hilfen.de/en/grammar/if_type3.htm         
http://www.edufind.com/english/grammar/if_conditional6.php
http://www.ego4u.com/en/cram-up/grammar/conditional-sentences/type-3/exercises
http://www.learnenglish.de/tests/conditionals/testtype3.html
http://www.englishexercises.org/makeagame/viewgame.asp?id=3123
http://abdessalami.bravehost.com/if-clause.html
         
Grammar with pronunciation
http://www.shertonenglish.com/resources/es/conditionals/type3.php

Exercises mixing all types of conditionals: http://www.nonstopenglish.com/lang/es/allexercises/grammar/grammar-conditional.asp