The effect of chain stiffness and entanglements on deformation properties of end-linked networks was investigated using Monte Carlo simulations. Tetrafunctionally cross-linked monodisperse networks were prepared in the framework of the bond fluctuation model (BFM). The degree of entanglement in these networks was tuned by changing the initial polymer concentration at curing (Phi(0)). The chain stiffness was controlled by using an adjustable bond angle bending potential. Continuum-space simulations of isotropic swelling and uniaxial deformation were carried out in isobaric and isostress ensembles, respectively. Both equilibrium swelling and stress-strain data indicate that the stiffer chain networks are more entangled, confirming previous simulation results on polymer melts. For such entangled networks, stiffer chains are associated with a higher elastic modulus and smaller equilibrium swelling; the opposite is true, however, for entanglement-free "diamond" networks. The elastic modulus determined from low-strain uniaxial deformations agrees with semitheoretical predictions for moderate chain stiffness, but not for very stiff chains. For the realistically cross-linked (and hence entangled) networks studied here, the theoretically predicted strain-induced discontinuous ordering transition was not observed, although the transition region becomes narrower for the least entangled networks made from the stiffest chains. Entanglement-free diamond networks do exhibit a discontinuous transition from a disordered state to a nematic-like state under uniaxial extension.