When doing your pilots license in Australia, you need to get your Student Pilots License, obvious. To get it done though, you have to go through a process of CASA forms and various other checks...
The steps to your student pilots license...
1. ARN Application - Form 1162
Complete Form 1162 (Aviation Reference Number application) to get your Aviation Reference Number. You can fax, email (scanned copy) or post it to CASA. There is no cost associated with this step...
You will need your ARN for everything you do as it is your unique ID when dealing with CASA.
2. Medical Certificate
You need to get a CASA designated Aviation Medical Examiner to perform a medical. No problems, but which medical do you need done?
When your a student pilot, you just need a "Class 2" medical. Details of when you need the other types can be found on the CASA site here.
You can't get your medical done until you have your ARN.
3. Security clearance
Next you need to be validated as not being a nutter. So you either need an AVID or an ASIC clearance. The AVID is the basic security clearance, there the ASIC is the more detailed security clearance. Basically if you need to fly into or out of a security controlled airport, you need an ASIC. My flight school recommends the ASIC. It costs about $15 or so more than the AVID and seems to take about the same 4 weeks as the AVID.
For the AVID - Form 499 Aviation Identification (AVID)
For the ASIC - Form 498 Aviation Security Identity Card
The requirements for each is different, so visit the info on the CASA AVID/ASIC page for which one to do. In the "Your questions answered" links, the details of the costs are buried in there.
By the way, with this application you will need to provide two passport photos, your medical certificate and a bunch of certified copies of specific documents.
4. Student Pilot License
Finally, the Student Pilot Licence. Fill out the relevant sections of Form 497 - Student Pilot Licence. The instructions cover off what needs to be filled in.
With this application you will need to provide 2 passport photos and certified copies of identification. You'll typically need to meet with the Chief Flying Instructor with all the documentation and your "English assessment" completed...
You can do steps 3 and 4 together to be more efficient :)
There will be more, such as radio, PPL etc. But I've got no idea on how that works yet...