Leaving for Seattle on Monday! I am looking for a good walking tour of the city. Any suggestions?

Also, do I need to reserve Victoria Clipper ferry from Victoria to Seattle or can buy tickets on the spot?
Thaks in advance for your advice.

What hotel are you staying at in which neighborhood? If you are downtown, just ask the concierge for a map and go for it. Downtown core is small and walkable. You will want to spend time at Pike Place Market and along the waterfront. While you're there you can check on the clipper.

The usual walking tour of downtown Seattle goes from Pike Place Market to the waterfront and then south to Pioneer Square.

The Olympic Sculpture Park is at the north end of the waterfront and the International District (Chinatown) is just beyond Pioneer Square.

Walking neighborhoods near downtown include Capitaol Hill, Lower Queen Anne, Madison Park, and Fremont.

Also, see: http://www.seattle.gov/tour/HistoricDistricts/index.htm

Re the Victoria Clipper, if you have flexibility as to which day you go, check out the 1/2 price ticket booth at the Market Info desk--sometimes they offer last minute half price trips on the Clipper (usually mid week).

But if you know you want to go on a specific day then I'd reserve in advance to be sure you have a spot.

There are organized walking tours of the Seattle Underground in Pioneer Square, if that's what you're after.