I think that the Wikipedia pages will provide you with the best explanations and the best images to help your understanding.
These days we use devices similar to the CCDs in your cameras (only bigger), have a look at this page on the
Hermetic Detector built for the LHC at CERN.
There is also an interesting
lecture by Don Glaser, the person who invented the bubble chamber. It is about an hour long and gives a very good insight into the world of academia.