In 1.5 only the way to texture a block and item changed, not the rest of texturing methods. So to texture my blocks and items I created a new folder in my mcp\src\minecraft and I called it textures. Then inside the textures folder make two folders, one called items and one called blocks.
Now go into your eclipse program and go to your the main class file you are using for your mod. Go to the line that your set the unlocalized name which looks something like this:
YourBlock = new YourBlock(700).setUnlocalizedName("YourBlockName");
The String in the brackets after .setUnlocalizedName is what minecraft will automatically try and load a png file for in textures\blocks. The png it will try to load in this case will be in this location: mcp\src\minecraft\textures\blocks\YourBlockName.png
To make it load your texture for the block just drag a png file named whatever your setUnlocalizedBlockName string is into the \textures\blocks. Then go into your block class file, and remove any texture loading you have coded previously.
Do the same for items, but instead put things in the items folder, not blocks.
If you have any issues look at the console when you run the game. It should tell you if itis trying to load a texture, but cannot find it, and if so where it is trying to load it from. That is how I figured out how to do them in 1.5.
Hope this helps
- Sky
