design pcb

how to desine pcb in easiest way at home

Use software on your computer. I used to use express pcb but found Diptrace is better. Both are free downloads.
here is a list of guidlines http://www.alternatezone.com/electronics/files/PCBDesignTutorialRevA.pdf
I have a DIY post on making home brew pcboards over at http://digital-diy.com/general-electronics/361-printed-circuit-boards-diy.html

When you say "design" are you talking about just the _design_ part, or the whole process (i.e. CAD, print, etch, and even soldermask and silkscreen)?

If just the CAD [layout] part, then refer to Mr. Bezaire's comment or consider Eagle CAD (only because of SparkFun's excellent tutorial [http://www.sparkfun.com/tutorials/108]) You can get it here:

http://www.cadsoftusa.com/downloads/freeware/?language=en

..and here's a little more Eagle help:

http://hackaday.com/2009/01/15/how-to-prepare-your-eagle-designs-for-manufacture/

If you also want to do the dirty work of actually fabricating the board:
* If it's because of the expense of getting it done commercially, then consider Batch PCB: http://batchpcb.com/index.php/AboutUs
* If it's because of the down and dirty aspect of it (or you're just a "hands on" kind of person) then there is a wealth of information behind the following Google searches:
- "make your own pcb"
- "toner transfer pcb"
- "photo resist pcb"
- "dremel pcb"

thank

Eagle is also free for download as well or if you are sensible and can get someone to agree working with you

There is what we call applications sharing which you can do via messenger " Find out how useful this is very if you need to share resources " Also very clever avoids the need for licenses across the net

It’s a another way round the problem of costs

Thank you, I forgot to mention that it's free to download (with limitations).

Diptrace produces all required GERBER files for a board house (silkscreen, solder-mask etc)
First you design your schematic then go to the PCboard screen.
Diptrace even does 3D
Everything I have seen Eagle do, Diptrace does as well but a easier learning curve.
A very reasonable PCboard house is http://iteadstudio.com/store/index.php?main_page=index&cPath=19_20
Have had boards done as little as 10 for $9.95
A quality board with all the bells and whistles you could ever want.