http://jp.hujiang.com/subject/pronounce/default.htm This is a Chinese Website for Japanese learning. Click on the character you want to learn and you can hear the pronunciation. You can switch between katakana and hiragana by clicking the tabs above the table. Hope that would be of some help. :)

I introduce two internet site to learn Japanese This site can learn any things. http://www.guidetojapanese.org/learn/grammar/writing this site is letter practice Japanese http://www.nkc.u-tokyo.ac.jp/support/e-learning.html many other site give you free instruction each type is little different by site by site this is just a sample. Youtube also provide Japanese lessons also check.