PCB Design Tutorials
Eagle CAD
Here is one for EagleCAD, another one, one on instructables, one as a PDF
How to get Gerber files out of EagleCAD
You cant just send eaglecad files...you need to generate drill/rs-274x data. In the latest version of EagleCAD i believe you dont need to run the drillcfg.ulp anymore.

Another one from pdx.edu

SparkFun has another tutorial for their PCB service which has a script for increasing the silkscreen width, which may be useful with other services

May 17, 2011 20:07