A couple more things:
When coming from the Sound I always duck under the railroad bridge asap because you never know when they will close and that could cost you a cycle or two in the locks. There is plenty of room and depth to do donuts or just drift and wait up near the dam/spillway where it widens out. I does shallow a bit on the very SW part, which dries out at low tide, keep an eye on that. There's a wall on the south side where you can side tie, (either side) and wait if there's room and its highish tide. Most of the small yellow bollards are ripped out so be careful tying to the wood beams as there are spots of gooey tar. Use your old black lines. At low tide it's full of barnacles and I avoid tying there and just do the donuts..
The small locks seem to be about 28' wide so our F31 had just a couple feet on either side. If you are 26' or wider you might be diverted to the large locks.
When entering from the Sound the current is against you so bump up the throttle or it will take you longer than needed to enter, plus it gives you better steerage. Conversely, when exiting the locks toward Shilshole don't be fooled by the current pushing you along at a knot or three, thinking you have steerage at that speed. You don't, so be cognizant of having enough throttle (steerage) to not be pin balling off the walls. It's exciting because your ground speed, as seen by the lock walls whizzing by you, will be 4-5 knots! This is especially noticeable if you are the first boat to exit: Heads up, and be ready with the throttle to give you a couple knots of through-the-water speed! Going in and out, my head is on a swivel, constantly looking side to side at the lock walls to keep me in the center. After probably 30 or 40 transits I haven't hit anything yet.
The locks do have green and red lights for when to enter or stand by. Look for those at the very end of the jetties. Sometimes the empty lock will have a red light. Lucky you, there is probably a commercial boat coming up behind and will take (your) spot for the next ~30 minute cycle. Do keep an eye on the light, though, because they might turn green without warning and someone may scoot in ahead of you. However, my experience is that every boater is aware of their place in line and will give you the opportunity to go in your order (of arrival). Be ready to go though, as everyone is anxious to get into and out of there.
When you approach the locks they may hail you on a loudspeaker. Usually I can't understand what they are saying and just continue to putt putt in til I hear otherwise. On the Shilshole side they will often have a guy standing high on the wall giving hand or voice signals where to go, so look for that.
The book says you need to have four 50' lines but usually you don't need them. I do have them tied to my cleats on all four corners and flaked out. I also have my normal ~25' mooring lines as they are usually handier to work with if I'm diverted into the large locks where you'll likely be rafting to a bigger boat. But be ready to use the long ones if the lockmaster asks for you line. The lock employees are very helpful and friendly and will often take and cast off your lines, making it easier. I've single handed many times thru the locks so it can be done. I put out 3 fenders a side with 2 extras handy, one on either side, in case they are needed in a hurry at a specific spot.