The programs you downloaded should have installed automatically. The .dmg files are what downloaded. You can delete these. Try restarting your computer, then you should be able to delete these files and empty the trash. Sometimes the computer still "sees" these .dmg files as being active until you restart.
I am a totally new Mac user and am struggling with the concept of these .dmg files that are downloaded to my desktop when i install a new application (example firefox) and then when i try to delete this file after the installation completes it appears the program requires this to run?
What do you typically do with the files after installaion? Is there a default setting someplace that tells the OS to dump and store these some place else in my HDD?
I also dont understand the icon that then gets placed on my desktop of the (in this example) firefox application... it looks like a new drive but its actually how i start the application? is it the equivalent of a link in windows or is that the .exe and my default file save settings are screwy?
Help! I want my Windows Pc back lol