<IMG src="http://www.iloveclocks.com/Cuckoo_I/Cuckoo_Clock__C-2/125L.jpg">
There should only be one set of quotes around the URL of the image.
<IMG src="http://www.iloveclocks.com/Cuckoo_I/Cuckoo_Clock__C-2/125L.jpg"> should work.
Don't be discouraged - HTML is wonderful but totally unforgiving.
Try it again!