That is quite a beautiful map~
Here's how to upload it if your having troubles still.
Step 1. Make a Mediafire account.
Step 2. go into your account, and click upload. Upload from computer.
Step 3. Export your map, and get together a neatly organized download. Then, make a zip, name it whatever, and put the exports, MP3's, and all kinds of sturf you need to fit in. No objects or skies. Those are exported already, and sturf. MP3's, water textures and materials however aren't.
Step 4. Leave your organized ZIP somewhere, and make sure it's organized. Put a readme in there if you want to. Stuff you exported put in exports, MP3's put in music, sound MP3's put in sound, materials in materials, water textures in textures, I think...
Step 5. Do Step 2, then click anywhere in the middle of the uploader. The thing that popped up. If it didn't pop up, just try again I guess?
Step 6. Click on your .ZIP file. Then, wait for it to upload. Tada! Done. Copy the link and hand it out now! :3
Anyway, this map looks like it had a lot of effort put into it. :3 Looks beautiful!