Hi all, and thanks for the replies! Here's more details.

Location: Amy Yee Tennis center
http://www.seattle.gov/parks/athletics/tennisct.htm

Length/Number of Matches: Weekly from Jan 7th-Feb 17th

Day/Time: Every Friday night, 6:45-8pm

Cost: Cost is a one-time charge for the entire session, $110.00

How: You will need to sign up for course#24777 Mixed Team USTA 3.5
Mixed Doubles. You can sign up with your SPARC (Seattle Parks and
Recreation) account at:
http://class.seattle.gov/parks/Start/Start.asp?
SCheck=110666569&SDT=39421.5193402778 First you will need to co and
great a PIN and get a barcode (your username and password).
Registration begins tomorrow, Thursday, Dec 6th at noon. If you would
like to play and are willing to commit to the session, I'd love to
have you as a partner. Please let me know if you're in for sure, and
we can coordinate registration tomorrow. It's a fairly complex system
but once you're in it gets easier and Amy Yee is a good indoor venue.