What to do once done?

I have a question about what to do with some things once I'm done with them. For instance, I just downloaded MainMenu.dmg and now the paper with the HD on it is on the desktop. What can I do with this to get it off the desktop? I really don't want it anywhere, can I just put it in the trash or will it uninstall MainMenu when I empty the trash?

if you proper installed it via an installer or drag and drop to your apps folder than you can drag it to the trash...most likely the trash will turn into an eject symbol, but it will still delete it
-chris

Ok, that worked. What am I supposed to do with the icon that comes up on the desktop? Can I just drag that in the Finder or something?

And I have OnyX installed now, and let it do its thing.....and I have MainMenu too now and it has done its thing, and nothing is helping. The only thing I can tell different is that Apps take longer to open. Is this doing more harm than good??? Thanks........................