Here's a good one I've seen that's pretty recent: https://forums.tigsource.com/index.php?topic=46126...

http://pixeljoint.com/forum/forum_posts.asp?TID=11... Comprehensive and very helpful for avoiding common mistakes.

http://gas13.ru/v3/tutorials/sywtbapa_almighty_gra... I learned a lot from this one.

http://manningkrull.com/pixel-art/walking.php This is just a tutorial for making walk animations for side scroller sprites but it helped me understand walk cycles in general.

http://2dwillneverdie.com/tutorial/ Lots of good tutorials with tips that are the most useful for larger peices. It's advanced stuff, don't start with this one.

just browse pixel joint a lot, sit and try to create your stuff :).

Best tool to create good pixel art? A good art background. If you know a little about drawing (color theory, perspective etc) the right pixels will come to you!