Here is a document called Radioactivity all which in three pages will tell you almost everything you need to know about alpha, beta and gamma radiation, including uses.
Look at the blog post on Half Life here. If it’s a little bit too complicated, you can remind yourself of the classwork on half life by clicking here on the Half Life of Iodine 131. You also should know about Handling Radiation (short version) or in more detail here
A description of Rutherford Scattering is here. It’s quite detailed but you only need to know an outline of how the experiment was done and the staggering results it delivered.
You should also read the posts on Isotopes, Background Radiation and Radioactivity History There’s also a post on carbon dating the Turin Shroud here
John Vagabond's Physics and Chemistry Blog 