1. how do i make paper? Minecraft Wiki.
2. how do i find out my seed? F3, if on Mac, it should be alt+F3 or ctrl+F3
3. how can i get adventure maps? If you mean put them on your Minecraft saves, go to %appdata%>.minecraft>saves and extract the adventure map to the folder saves.
4. how do i download mods/texture pacs? Look up on YouTube for certain mods, and for texture packs...
Download the pack. Go to %appdata%>.minecraft>texture packs. Drag and drop the pack.
5. how do i change my prof pic on this website? My account>edit profile (or change avatar)

5. Go to 'My Account' and at the bottom it'll say 'Change Avatar' or 'Update Avatar'. Click on that, load a picture of the appropriate size (I recommend 500 by 500 picture if your making your own). Wait until it uploads and your done! If it takes for ever to upload, let it say 'Uploading File' for about 20 minutes and refresh the page, and it might appear (It's a trick I use to upload stuff). Hope this helped!

<1. 3 cane put on top of each other in a crafting bench
<2. 2 you cant until 1.3, then put cheats on the map and type /seed and it will show in the chat box
hope this helps

I can answer question 3 and 4
3.You can download them from planet minecraft
4.Download then put the mods into mods or minecraft.jar put textures by going to texture packs in the menu and open texture pack folder then put them inside