Beltane Ranch has a great page on things to do in and around Glen Ellen, including some recommended wineries. 

If you have kids, here are a few of the kid-friendly places/activities:

• Train Town -  20264 Broadway, Sonoma, CA 95476.  Open Monday through Sunday 10 a.m. to 5:00 p.m; www.traintown.com; (707) 938-3912.
• The Charles Schulz Museum - 2301 Hardies Lane, Santa Rosa. Summer hours are Monday through Friday from 11 a.m. to 5 p.m., Saturday and Sunday from 10 a.m. to 5 p.m; www.schulzmuseum.org; (707) 579-4452.
• Spring Lake Regional Park in Santa Rosa - 391 Violetta Drive, Santa Rosa. www.sonoma-county.org/parks; (707) 565-2041.
• Six Flags Discovery Kingdom (Napa Valley) - 2001 Marine World Parkway
  Vallejo, CA.  About an hour away. http://www.sixflags.com/discoveryKingdom/index.aspx