Welcome to Planet Minecraft! So first of all to upload, press "account" in the top right corner, that takes you to a page where you can manage your account, upload, and update your submissions. There are six buttons labeled; Projects, Skins,Textures, Servers, Mods, and Blogs. Click on the button that relates to what you're uploading, and I believe it has directions for each kind of submission when you click on it. Then, for making skins, there is a wide variety of ways. I use Skindex, which has Steve and Alex models, and Overlays for both. Another I know of is Miners Need Cool Shoes, which only uses the Steve model, includes Overlay, and has separate layers, which is pretty cool. Like I said, there are many things like the two I named. When you're done with your skin, download it and save it wherever. I have no clue on how to make maps, but many others do. Finally, to change your profile pic you press "Account" and go to "Edit Profile/Settings" or "Change Avatar", they go to the same place. Then click the little pencil and paper icon in the "Avatar" section, and choose an image or make your own. I hope this helped, I've never been good at explaining. :)