NOAA's ozone page -- nobody does it better than NOAA.
The definitive ozone hole page, with more links than you can possibly visit.
Another exhaustive page, this one from the EPA.
A dissenting view of CFC's.
One of the freon replacements.
There is an enormous glut of global warming information on the web, so I'll keep it short and simple by giving just the EPA and NOAA links. Also, the NOAA climate page.
Again, just the EPA.