Like every electronician, when we design some electronic, we
need a schema editor and a printed board circuit maker.
Thanks to Free Software, you can find the first on gEDA and the second one on PCB.
Their development continue actively.
You can find here the files for the LinuxFocus
article355 about the toolchain gEDA and PCB.
If you lack some electronic knowledge, you can find here some very
good free books about it (or if you master electronic, you can give a
hand to achieve them) and on the other hand, if you are at electronic
top, you have fools on http://www.f-cpu.org
who want to make a 64 bit processor.
And if you are from the french community, you can find more stuff on
the french page.
You have some questions, you have seen a mistake, write to me.