I went for the first time last fall with my little sister. We had a great time! We didn't make any huge purchases, but now that things are coming a long more in the house, I will be on the look out. We did take lots of photos though...
Junk Bonanza takes place at Canerbury Park in Shakopee, MN. It spans over three days and is inside, so it is happening rain or shine. This year's spring dates are Thursday, April 18th to Saturday, April 20th with times varying on those days. Admission cost $9 at the door and there is also an early bird time frame where you can go in two hours before the doors open on Thursday.
There are a ton of venders with a wide range of things from antiques and collectibles to unique, handmade items. All of the information is available on their site.
Check out my two part post from last year here and here!