Links to online lessons and videos explaining the conjugation process for -ar verbs in the present tense in Spanish
http://www.youtube.com/watch?v=gmjWWphCx5k
http://www.studyspanish.com/verbs/lessons/justar.htm
http://www.123teachme.com/learn_spanish/ar_verbs_present_tense_conversation
http://www.davidreilly.com/spanish/lessons/basic_verbs/ar_verbs.html