It is not as difficult as you would think. In here you will find information about everything from Extract to All Grain brewing. The difference gives itself away in the name really.
All Grain is simply to brew your beer from the ground up. Extracting your own wort from malt grain by heating water and mashing it, add hops and possible some spices, just like a brewery would do it. Using extract brewing, half the job is done for you by making the extract and packing it in concentrated form. You will still have to boil up and add hops and yeast though. This might be an easier way of brewing and requires less equipment. This is just two examples though, so lets not twiddle thumbs.
Click on one of the links below and let me show you how it is done.