YAY!

[Highram]

On the submit page is has a subtitle saying "Which file?".
You want to follow the box it connects you to down to the bottom of it where there are two buttons saying "Add a file" and "Add text". If you want to add art you have to click "Add a file". Be warned! DA only takes .png and .JPEG images and .GIF animations. So Photoshop files (.psd) won't show up for you to click on. You click on the file you want then wait for it to load. Once you see a miniature of the image, you can submit the picture as a whole.

One more thing seeing as you're new to this. Keywords are anything that's related to the image. If I draw a picture of a purple cat, and put "purple" and "cat" into the kepwords then after submitting it put "purple cat" into the search bar, the picture should turn up.
I like to put my username in there.