A solar eclipse happens when the moon casts a shadow on Earth, fully or partially blocking the sun’s light. Observers within the path of totality will be able to see the sun’s corona (weather permitting), while observers outside this path will see a partial eclipse.
The experts at NASA have a wealth of informaiton on their website.
They also put together a handy two-page guide:
In Whatcom and Skagit County, the eclipse will begin on Monday, August 21 shortly after 9am, reach its peak around 10:20 am, and finish shortly before noon. We will see approximately 90% of the eclipse in Whatcom and Skagit County.
WARNING! Never look directly at the sun without proper eye protection. You can seriously injure your eyes. Use protective eyewear approved for eclipse viewing or build a safe viewing device.