I have gotten a couple of emails lately from people relatively new to the global warming topic who would just like to find a site that has updates on the earth’s actual temperature and CO2. Unfortunately, that’s not quite as straightfoward as one might expect. Measuring temperature, for example, is quite similar to the old proverb "he who has one clock always knows what time it is; he who has two is never sure."
That being said, this is an excellent summary of temperature and CO2 from several sources, as well as a good overview of how these sources differ. The person who puts the site together is a skeptic but the data sources are the actual data and he is careful to include even those data sources (such as the GISS) that skeptics think are exaggerated.