Junipers are strange conifers indeed. Their fruits look like blue berries and their leaves may be either scale-like or needle-like. In fact, their fruits are round cones, but they're softer than most and they have a blue, red, or copper color. Junipers bear male and female flowers on separate trees, so only "female" trees have fruit. Juniper foliage may be scale-like, needle-like, or both, and it often has a distinctive odor that can be smelled from quite a distance.
Three junipers are native to the Pacific Northwest, but chances are good that western juniper is the only one you will see. The other two are Rocky Mountain juniper and common juniper, which grows primarily near treeline. The Pacific Northwest's junipers do not typically grow together.
For more information on the junipers native to the Pacific Northwest, go to the species page or see p. 24 of "Trees to Know in Oregon".