Inexpensive Software to Design PCBs

3D Model of PCB

Kicad is Free and Open Source (FOSS) software to design Printed Circuit Boards (PCBs).  Although it is lacking some design features, this is the way to go if you do not want to use proprietary software.  I've found the software to be somewhat buggy on Windows.

I've used Eagle CAD for many years.  This is easy-to-use proprietary software.  If you are a student or in academia, you can obtain a free educational license.  Eagle is somewhat quirky since you always have to keep two windows open at one time for schematic-to-PCB annotation to occur.

Altium Designer is probably the greatest PCB design software ever created.  Component footprints and schematic symbols can be easily downloaded and placed into your CAD design.  This software can be considered as the Microsoft Word of PCB design software since it allows for easy copy-and-paste of designs.  Although the software can be expensive for companies, you can obtain an reduced-cost yearly academic (student and teacher) license from Altium.