To Start downloading a file,when the new URL dialog box appears, make sure that the "start immediately" checkbox is marked, and then click the "OK" button. Or click "new" on the toolbar and manually enter in the information.
After you click OK, the download will start and appear in the main application window. If you did not check the "Start Immediately" checkbox, the download will be put into the main window, but will not start. You will have to manually select the item and click "Start" to start downloading this file.
If the site requires login/password information, you can enter this information if you enable the "Use Login Info" checkbox. You can then manually enter new login information, or if this is an account you have saved before, click the select button to bring up the password management dialog. If you want to save the current login information, click Save As... and this will allow you to set a name for this account for later use.
If you want to quickly add files to GetGo without showing the New Download Dialog, make sure this option is checked.