Once you have an id (and an ego too hehe), go to the gridcosm current level and find the square you want to work on. Click the reserve button and you have two hours to complete an image to fit in that space. It is 150x150 pixels and the image you upload must be a JPEG or a GIF. Once your image is ready, save it in a place it will be easy to find and then go back to the gridcosm current level. The square you selected now has an Upload button. Click on that and follow the directions. You will be asked to "give it some textiness" this means you can add a phrase or something to gridpoem, it may be related to your image or the rest of the poem or whatever you want.

If you're not hip to it yet, I'll let you know that folks 'round here like it if you make your image blend smoothly into it's surroundings. Have fun!