Puzzle can be used for two things: Creating tilesets and exporting/importing the textures. To begin, we'll be importing a brand new tileset that we're going to use in New Super Mario Bros. Wii.
Save this image
to your computer, as we will be using this as an example. The texture is just a recolour, I know, but do remember this is for a tutorial so you understand how it works.
Open up Puzzle and press File > Import Image... -- Navigate to the tileset you have just saved and open it.
The editor allows you to modify your tileset to your needs. On the right of the window, a bunch of options are given to you where you can apply attributes to your tileset. The options are pretty self explanatory, and are easy to learn. Play around with it a bit.
This isn't it yet though. In Puzzle, there is a tab called Objects. This is where you need to choose which tiles can be chosen to be placed in the level. This is where you will create slopes, floors, edges, bushes that can be used. For now, we will make a simple floor.
Press Add on the right. It will now create an object. To use all of the six unique grass tiles, press the + icon next to the tile preview down below. In order to draw the grass tiles on each empty square, you must first select the grass tile before clicking on the empty box. Whichever tile you have selected is the tile you will be drawing with.
Excellent! We now made a custom tileset! Go to File > Save As... and save your tileset as Pa1_CustomTexture.arc inside of the Stage/Texture folder. It will ask you if you want to compress it. You want to choose slow. If you choose fast, the textures will most likely tend to end up garbled. Do note that this might take a few minutes.
WARNING!! Press Tasks > Set Tileset Slot and choose the Pa slot to the tileset you're creating. In this case, we are creating a Pa1 tileset, meaning you have to set the slot to Pa1.
Open up your SD card, and save the file in nsmb/Stage/Texture.
To use your texture, open up Reggie and load your level. Press Ctrl + Alt + A to open the area settings. You now see a list of tilesets that the level currently uses. You want to change the Stage Suite. Select Custom filename and write down the name of the texture, in our case, this would be Pa1_CustomTexture -- Do not write down .arc! Or else it will not work!
If done correctly, your tileset that you've put together will now show up in your palette browser. It should be on the second panel. If this is not the case, post a reply with your issue and I will gladly help you out.
If you have any questions, feel free to post in this thread! Me or other NSMB Wii hackers will answer your question and try to help you out as much as possible!