I have been messing around with the code and i have finally figured out where the texture's go for developers. If you're having trouble with your textures and your textures in game are black and pink checkered then this should work for you. This isn't my favourite way to put your textures but its the only way i've found!
To register your texture make sure you go to your pickaxe class (itemPickaxe.java).
This is the code you use to make your texture work!
Now the directory for the textures is in the 1.6.1.jar file.... I hate this way, but i think its the only way for now!
For Items -
For Blocks -