Dion's recommendations are what I would also suggest. Personally for pink and coho salmon, I have been using a spinning rod rated for 4 to 10lb test in the tidal portion of the Fraser River, sloughs, saltwater, small streams where little amount of current is found or the fish are not exceptionally big (12lb or less). I have been using a 8' Fenwick HMX spinning rod, coupled with a Shimano 2500 spinning reel (as for which model, go with the best you can afford). I find 8lb test Maxima Ultragreen goes well with this setup (6lb test tends to have lots of abrasion after a few fish, 10lb test is a bit awkward to cast with this setup). I bought two of this spinning rod from Berry's Bait and Tackle.
For rivers with stronger current and where fish maybe larger, a higher weight rating is necessary. A longer rod may also be good, for better line control in the current. I actually just use my 10'5 baitcasting rod when casting spoons in rivers such as the Squamish or Chilliwack River.