If you want to save it in a saved game, so other people can play your game with aditional scenery, look in the options menu. There is a check box with something to the effect of "Export Scenery with Saved Game."If you want to know how to add scenery, you have to move the file into a certain folder (not sure which, but its one of the data folders, I think.) The normal loading bar will have a different caption on the top, so you'll know you did it right. Then, in the scenario editor, the new scenery/ride/whatever should be in a menu. Which one? I don't know, depends one what it is.
If you use a floppy disk, you'll take a while (depending on how many files you have). I have a USB flashdisk which holds 64MB, so I can copy all the files at once. If you have alot of files to tranfer over to another computer, I'd recromend buying a USB flash disk. I've seen them as low as $20.00. Mine was $40.00, but the price varies by the amount of memory this thing can hold. To move ur files, just copy the ones you want and put them in the folder with the disk. Then just load the disk on the other computer and copy the files in the RCT file folder in the same spot they were at on the original computer.
Moving files around to different computers is easy. zjohn covered flash drives well. I got mine for 120, and it's only 64 megs. But, I paid mostly for the MP3 player portion of it.But, if the computers are networked together, you could also enable file sharing*, and put the files in a shared folder (assuming you're using Windows, and I'm sure you are if you need help, no offense.) Another method would be set up a FTP server one one computer, and a client on the other. Don't ask me how, I know, but I'm a horrible (and impatient) teacher. Lastly, try an AIM file transfer.The easiest if the computers are in walking distance of eachother, and not networked, would be a USB flash drive. If they are networked, file sharing would be best. If both are on the internet, but not networked together, FTP would be the next best soultion. Lastly, you should use those archaic magnetic storage disks that hold next to nothing. My computer doesn't even have a floppy drive (mostly because the color of the drive clashes with the case. )*File sharing does not refer to Kazaa, BitTorrent, Grokester, or any other peer to peer service. It is a component of the Windows OS used in a LAN.