LTspice IV is a fantastic simulation program provided free by Linear Technology, one of the great IC manufacturers. This is a very good general purpose spice simulator that is unbeaten for simulating LT's switching PS chips. There is a Yahoo group for users of LTspice where you'll find many good examples and tutorials.
Check out the PCB fonts page for information on using special characters in Protel.
After designing a PCB and before sending it to the fabricator I always make sure I can read the design with both of these Gerber viewers:
Last Updated 03/30/2013