Sure, getting the GERBER files to make PCBs from me is great but how do you turn them into actual PCBs? There are a lot of options and some are better than others. Here are a few that I have used that I have had no problems with:
PCBWay - Located in China. Pretty cheap. Can do assembly, both through hole and surface mount for acceptable prices.
JL PCB - Located in China. Great prices. Can do surface mount assembly for very low prices.
OSHPark - Located in the US. All those "purple" boards people make and sell probably come from OSHPark. They can be a bit slower compared to PCBWay and JL PCB.