Here's one that's 16 x 22 with a link to pdf plans:
http://www.rona.ca/webapp/wcs/stores/servlet/ContentServlet?assetId=1030&langId=-1
Here's another one for a 24 x 24 that they will email you the full plan in pdf:
http://www.cadnw.com/free.htm
Hope this helps ....
Here are some less expensive plans:
http://www.designs-usa.com/Woodworking%20Plans.htm
And a free one:
http://www.buildeazy.com/fp_gazeboimp_0.html
Jimi
Try the Scott's website (www.scotts.com). They have a lot of information including a monthly email that you can sigh up for that gives detailed information for your location / lawn type. Hope this helps ...
Jimi