I'm not too sure about podcasts or YouTube channels, but here are the Japanese study apps I have on my phone:
-Mochi (Lite): Has Japanese Language Proficiency Test vocabulary (N5)
-JukuNx: Has JLPT vocabulary (N5-N1) +Quizzes
-StickyStudy: Has JLPT kanji and vocabulary (N5-N1), Heisig (5th edition) -Kanji, Joyo Kanji, New Joyo Kanji, School Grades (1-6)
-Kanji Dream: Kanji and vocabulary.
-Kotoba!: Japanese -> English/English -> Japanese dictionary
As for websites... I'm not too sure.
Maybe
http://japanese.about.com/?
You could also try the 'Japanese Language' subforum (or other learn Japanese guilds on Gaia). (゚▽゚*)