choosing the right fuse for a PCB
Check out a resettable fuse such as a PTC:

http://www.littelfuse.com/products/resettable-ptcs.aspx

The PTC comes in regular packages like 0805 and through-hole just like your other capacitors and resistors. When the current through the PTC exceeds a certain limit it heats up and the resistance increases, reducing the current to your board.

Once you turn off the power and the PTC cools down then the resistance decreases and after a while you can use it again, making it resettable. It's not perfect so if you keep tripping the PTC repeatedly you may need to replace it eventually, but it's good for a couple of uses.

I'd recommend having a LED before and after the PTC so you can tell when input power is applied (first LED turns on), and when the PTC has tripped (second LED turns off).

To pick your PTC you need to look at:


The voltage used by the circuitry on your PCB
The hold current, how much current can go through the PTC normally (your expected maximum load)
The trip current, how much current is needed to make the PTC start 
increasing resistance and limiting current to your PCB.


You can do a parametric search from most manufacturers to focus on the products they offer that fit your requirements.