Rat Lab 
This non-profit website spreads the joy of science to folks considering a career in science and those who are simply curious about how the world works.
My favorite section is the Top Pages area. Under this heading you will find links to so many great how-to, experiment, and answers that it deserves to be mentioned first. For example in this area you can find out how to extract DNA in your own kitchen, find out why you never see baby pigeons (hilarious), and learn how to make pH indicators, as well as meet the lab rats in Scientist profiles.
The navigation along the top has the section Articles, Try This, Facts, and Profiles.
You can also get to the Articles section by scrolling down the front page to the Read This section. Here you will find articles on many different subjects, such as choosing a PhD, or TB research, or a day in the life of a final year PhD student.
You can also get to the Try This section by scrolling down the front page to Do Try This at Home. You will find great experiments that you can and should try at home. There are three pages of experiments with some everyday things that you probably already have around the house or could easily buy for the experiment. This is a great section for science teachers or for some rainy day experiments to try with your kids. Not only does it give you great experiments to try, but it also answers some questions like why does this work, and then usually a more general question. For example: the pH experiment has the question what is pH at the bottom of the page.
You can also get to the Facts section by scrolling down the page to Strange but True. Here you will find a compilation of really interesting facts. Why do we close our eyes when we sneeze? This a great section filled with amazing information.
In the Profiles section, you will meet the scientists, err, lab rats. You can get here from the Scientist Profiles link under the Top Pages area.
This site is a fun, humorous look at science. It keeps it fresh, and explains why some people really dig science.