Conferences coming up
I've never been to the Garden Tourism or Reclaiming Vacant Properties conferences, but I have attended Main Street and American Planning Association conferences, and I heartily recommend attending any of these conferences if you are able.
I've only been to APA once, but the two tours I went on (Richmond, Baltimore) were some of the best conference tours I've ever attended, and three of the sessions in particular have had significant impact on my outlook on planning ever since (San Francisco and industrial lands planning, David Barth and parks and city planning, and Mayor Joseph Riley of Charleston's approach to urban design). One of the things I recommend too is going to sessions on topics you know nothing about, in order to challenge yourself (that's how I ended up in a session about Cerda and Barcelona).
Typically, conference presenters are a mix of practitioners, academics, authors, and advocates, so there's a good mix.
North American Garden Tourism Conference
March 16th - March 18th
National Main Street Conference
March 30th - April 2nd
American Planning Association
April 18th - April 21st.
Reclaiming Vacant Properties
Center for Community Progress
May 19th - May 21st.