A good general start off point belongs to Betsy Thorpe. She has a blog entitled http://nashvillepastandpresent.blogspot.com/ (Click on the link in my side bar)
It has a really good mix of history and what's happening in the community currently.
One of the upcoming events is A Tour of Nashville's Community Gardens on June 13th.
A really fun activity on the 12th is the Full Moon Pickin' Party sponsored by Friends of Warner Parks. Bluegrass under the full moon with jam sessions and lots of good food. More info at www.friendsofwarnerparks.com
Finally - the CMA Music Festival is this week 11-14th. Expect downtown to be congested and watch out for changes to traffic flows. The opening parade is tomorrow.