Trout might be a little difficult on most lakes this time of year as they are probably down deeper with water temps where they are. Best bets would be spiny rays. Not sure about boat rental places. Lake W North end or Arboretum should be good, Lake Sammamish is always good for bass and perch. I would check out Mike's website
http://www.washingtonlakes.com for great information on local lakes. Also the WDFW web site has a list of local lakes by county that they support and what is in them. Good Luck