A simple example of the * and & operators.

pointers.c

/* Pointers!
 *
 * Address of and value at...
 *
 * See this great stack overflow answer for an additional
 * discussion on the topic.
 *
 * https://stackoverflow.com/a/2094715/182778
 *
 */
#include <stdio.h>
#include <stdlib.h>

int main()
{
    int i = 42;  // A plain old integer.
    int *p = &i; // A pointer to i's address.

    // Let's see some info about the integer's memory address & value.
    printf("--- i is an integer ---\n");
    printf("The value stored at:     i = %d\n", i);
    printf("It's memory address is: &i = %p\n", &i);

    // Now, what about p?
    printf("\n--- p is a pointer to an integer (i) ---\n");
    printf("At memory address: p = %p\n", p);
    printf("The value that p points to is: %d\n", *p);

    // You can change the value of p!
    *p = 5;
    printf("After running *p = 5\n");
    printf("*p = %d\n", *p);
    printf(" p = %p\n", p);
    printf("&i = %p\n", &i);
    printf("     ^^^^^^^^^^^^^^ are these the same?\n\n");
    printf("But what is i?\n");
    printf(" i = %d\n", i);

    printf("* Gives you the value at a pointer\n");
    printf("& Gives you the address of a variable.\n\n");

    return 0;
}

pointers_and_structs.c

/*
 * This example illustrates structs & pointers to structs!
 */
#include <stdio.h>
#include <stdlib.h>

typedef struct Person {
    char *name;
    int age;
} Person;

int main()
{
    Person p;
    p.name = "brad";
    p.age = 12;

    printf("Name (p.name): %s\n", p.name);
    printf("Age  (p.age) : %i\n", p.age);

    Person *x = &p;

    printf("But x is a pointer to the Person as well!\n");
    printf("x->name: %s\n", x->name);
    printf("x->age:  %i\n", x->age);

    // But we can chnage the person thru the pointer, too!
    x->age = 100;
    printf("Name (p.name): %s\n", p.name);
    printf("Age (p.age):  %i\n", p.age);

    printf("x's address is: %p\n", x);
    printf("p's address is: %p\n", &p);

    // Just illustrating that we have one other variable
    // containing a Person type.
    Person o;
    o.name = "Ophelia";
    o.age = 35;

    printf("Name (o.name): %s\n", o.name);
    printf("Age (o.age):  %i\n", o.age);
    printf("o's address is: %p\n", &o);

    return 0;
}

Copy this code into pointers.c, compile it, then run ./pointers to see it in action.