Hi Ting -
One thing that I would add is to consider where you want to be with PC board design in a year or so. If you're planning on getting a job designing PCBs, or plan to join a company that uses high end PCB CAD, I'd look at CircuitMaker.CircuitMaker is produced by Altium and is very close in operation to their professional packages. The limitation with CircuitMaker is that all designs you create must be open source. The greatest strength is that it will teach you rules-based design, where you set up your design rules ahead of time, and then whatever you do follows those rules. It's a little harder to get started on, but in the long run, will teach you to be a better designer.Eagle is really easy to get started with, but you need to take extra care with the component libraries. I use Eagle more than any other package, just because it is really easy to learn and use, and there are a lot of tutorials available on the web.
Duane
