Parking will be along side streets by Tempe Farmer's Market within walking distance.  Arrive early.  Lots of vendors, some free, some have things to buy.  Bring your own water.  This is outdoors, wear appropriate protective wear.  This is also a march, so bring signs (anti-gmo), dress up, be creative and have fun!

For more info on the Free Block Party event:

https://www.facebook.com/MarchAgainstMonsantoPhoenix