Howdy Daryl,
To get to Lake Sammamish from your neck of the woods, take I-5 north to 405 north. From 405, take the I-90 east exit. Once you go through Bellevue on I-90, you will start to see Lake Sammamish in the distance on the left. To get to the public launch, take the Lake Sammamish State Park exit (#15, I think). Take a left at the light off the exit and follow the road to East Lake Sammamish Parkway. At the light for East Lake Sammamish (the corner has a Brown Bear Car Wash), take a left. After you turn, there will be signs on the left for the launch about 1/2 mile down the road. It's a piece of cake to find... Just follow the ski boats
Launch fee is four bucks unless you have a State Park Boat Launch permit.
I can't give you too much good fishing information, because I don't do very well on the lake. Here's the basics:
There are largemouth and smallmouth in the lake, but it is dominated by smallmouths. The largemouth can run big, up to six pounds. To target largemouth, most people look for them on the extreme north and south ends of the lake. Both of these ends have lily pad fields and pilings where the largies hang out.
If you run almost a straight line out from the launch, there is a large point on the left (SW) shoreline called Greenwood Point. This is the sunken forest area, and one of the only boating hazards on the lake. Looks for trees coming out of the water, and mind the no wake buoys. This is also a good area to start searching for smallies. A metro sewerline runs through this part of the lake (usually in about 20 feet of water) and there are a couple of creeks that flow in along this shoreline. Don't expect to be alone here, there are plenty of people who fish there.
When looking for the smallies, check out swim beaches, creek mouth, gravel points, and any deep docks you run across.
Sorry - long-winded
I hope that helps a little, Daryl. Now you just have to come back and tell us how you do!
Chris