Pad2Pad is a free PCB software that can be used to design, analyze, price, order and manufacture printed circuit boards (PCBs) .The Pad2pad free pcb software is very simple to use and require just few resources , it can work with an minimum requirements : Windows 2000/XP,Vista, 7, Pentium 233 MHz or higher , 128 Mb RAM , 26 Mb of free disk space . The installation package of the pad 2pad software has just few MB , so you don’t need a big hardware or an expensive computer .
TinyCAD is an open source schematic capture program that can be used to draw your own circuit diagrams.
Tiny CAD has an user friendly interface and is very easy to use . In TinyCAD you can lay out circuit diagrams using the supplied libraries or you can easily create your own symbols ( if you don’t find symbols you need ) . Also you can find many other libraries on the internet .
Once the circuit diagram has been drawn you can you can use some other functions of the Tinycad program for check your design, add symbol references , create parts list , etc.
Target 3001 pcb cad software is another useful program that can help you to design printed circuits boards .
Target 3001 is not a free software , but can be used for free with 250 pins limits if it is not used for commercial purpose , so you can use it if you use it for your projects .