Does it matter if its like this:

 

public static void main(String[] args) {

sayHello()

}

 

static void sayHello() {

System.out.println("Wuz gud");

}
 

 

OR this:

 

static void sayHello() {

System.out.println("Wuz gud");

}

 

public static void main(String[] args) {

sayHello()

}

No they both work, but it's generally best practise to write the methods under the

public static void main(String[] args) {
        sayHello();
    }

to get a better overview of the application. 

Best practice is to place a method below the method that is calling it. So that you can follow the code more easily from top to bottom.

This shows you all the coding conventions for Java (from an official source):
http://www.oracle.com/technetwork/java/codeconvtoc-136057.html

 

It tells you about spacing, brackets, naming styles, etc.