You're more than welcome to use my sprites, and as for uploading the game to the internet: First highlight the file on your desktop and select File > Create Archive from the Finder bar. Once you've created the archive you can upload it using a site like MediaFire:
http://www.mediafire.com/If you have any problems or if my instructions sound like gibberish,
too bad! Er, I mean... just say so and I'll gladly help.
Can't wait to see your game!