Hi planecrazy.eu,
About the airquiz website. It is good but I have noticed that some of the questions it asks are not covered in the usual PPL textbooks. For example, while preparing for my human factors exam using airquiz I had a body mass index (BMI) question that required specific knowledge of how to calculate a BMI, and what BMI values were generally accepted as overweight, underweight or about right. BMI is not covered in the Trevor Thom text books I am using to study and so I got the wrong answer but I dusted myself off and searched the internet for the information to ensure they wouldn't catch me out again. In the end I didn't get any questions about BMI when I wrote and passed the actual exam 5 days ago. Does this indicate that airquiz has questions in its question bank that are over and above the level necessary for a PPL? I'm not sure. I enjoy reading widely and deeply so it didn't make much difference to me.
You asked what online content there is so you can study in the interim. Here are my ideas for you.
You can
download the LASORS document from the CAA website. In particular some of the safety sense articles are a worthwhile read for airlaw and operational procedures. The air navigation order (ANO) is the document that describes the rules we must adhere to in the UK. You can
download it from the CAA website in CAP393. Section 2, Rules of the Air Regulations 2006 is the most important part for a PPL student. Both these documents are useful references once you have your textbooks.
You can create an account on the
UK MetOffice website and try to learn as much as you can about how to interpret the TAF and METAR information as well as F214, the low level spot wind chart. Those are the main weather resources used during the PPL but no harm in investigating the other items that are available there too.
You can also begin work on your radio telephony by
reading CAP413 the CAA's official publication on the subject.
Although not exhaustive, hopefully this list helps you and other's in similar positions.
splatt