Devilschild

Hey I'm in High School and new to electronics. I study Physics and can solder quite well. Im just wondering what is the best way to learn more about electronics without doing a course. I want to be able to read and construct electronic boards for home use, but dont have a clue what I am doing. Questions that have been bothering me: When I look at a schematic for something i want to build, i know what parts i need, but how do i know where to put them, and how do you join them on a PCB board? Also, where is the best place to buy PCB parts, i live in Australia and my local Tandy and Dick Smith Electronics do not supply most of the specific parts i need? Thanks for the help guys