Terry- First off WELCOME!! The answer to all those questions can be had with the local chapters. IIRC there is one in Longview/Kelso. Vancouver has a big chapter as well. Contacts are listed in the magazine and pick & shovel. You will be welcomed with open arms and a bunch of willing teachers. Vancouver, Portland, and the Brownsville chapters will be hosting the Gold Show at the Portlan Expo Center on April 9/10 this year. Drop by the joined booths and say HI. I know I will be there. Lots of vendors and equipment, usually with decent prices.
One of the first things you need to get is the Washington Gold and Fish booklet. That gives the states regs and such, and must be in your possesion in the field.