Well to start off there is Tacoma scuba center and his prices for service are very reasonable, as in tech diving and 02 cleaning, the nitrox-trimx fills are a bargain also,
There use to be a lighthouse diving and a underwater sports (chain dive shops).
Depending on where you are staying, there are shops in the surounding areas.
Bandito charters is the place you want to go and they will take you to all the sites that have the pnw sea-life you are looking for.
If your a comfy level with current, then there is day Island with easy access, sunrise beach with a long hill, Les Davis is also a shore dive area that is popular.
And there are plenty of shoredives all over the puget sound.
Once you get to the sites before the slacktides you will meet divers and could join them, or ask the geneal dive site info needed, if you dive solo. Pick up a copy of northwest dive news on the ferry or at terminal, there free and have alot of info needed for diving the area.
HAPPY DIVING