Fiber laser technology has the potential to make a significant impact in many defense applications, from LIDAR and remote sensing to high energy laser weapons systems. This emerging laser technology offers many intrinsic advantages over traditional DPSSLs. Widespread publications in the research community have demonstrated an impressive array of power scaling results, both CW and pulsed and at wavelengths from 1um to the eyesafe 1.5um and 2um wavelengths. Advantages associated with the technology are high wallplug efficiency leading to reduced electrical power requirements and easier system cooling, but also robustness, good beam quality and highly flexible system performance. These, coupled with (remote) fiber delivery options make the technology unique in certain applications. The topics to be covered include: an explanation of the basic fiber parameters, double-clad fiber designs and covering such concepts such as large mode area fibers, modal/beam quality, PM fibers etc.; rare earth doping and spectroscopy of Yb-1um, Yb:Er-1550 and Tm-2um; component specifications and availability (couplers, isolators, seed laser diodes etc); limitations to scaling fiber devices, non-linear limitations, damage thresholds, etc.; design rules and concepts for pulsed fiber lasers and amplifier chains, recent results from the literature; and system specifications and possible application areas, comparison and advantages over other laser technologies. This tutorial will cover the major aspects of designing and building a fiber laser, from the fiber itself through the various state of the art fiber components and discuss the system parameter space that best makes use of the intrinsic advantages of the technology.