Kicad
The KiCad EDA Suite project aims at creating a portable, cross-platform, Free/Libre/Open-Source EDA Suite. That is capable of schematic and printed circuit board design. The code is licensed under the terms of the GNU GPL.

Design Goals
Tools. The suite consist of a project manager, schematic editor, netlist converter, pcb designer and a gerber viewer.
Cross-platform. Works on Linux, Windows and experimental on Mac OS X.
File formats. It exports to many common formats like Postscript, Scalable Vector Graphics, Gerber RS274D/X, HPGL, DXF, Excellon.

Project Home Page and Tutorials.
Kicad Official Wiki.
Mini Tutorial from the Kicad wiki available here.
Home page of Jean-Pierre Charras Kicad designer.
Mini Tutorial by Renie Marquet is here in Portuguese only.
Kicad Yahoo User Group

Under construction. below is a PCB I created with Kicad.