I thought I would share my two cents worth!
I just moved into my first home and I am SOOOOO excited to have a backyard that I can dig into to my hearts content. Two things I have planned on doing for years are square foot gardening and composting with worms.
So I was searching on the internet for the best and most economical way to pen these little critters in and I found this
http://whatcom.wsu.edu/ag/compost/Easywormbin.htm Jeez I sure hope its okay to post links. I'd hate to get a tounge lashing my first day here!
Who doesn't have a million of these things laying around :-) Even if you don't they sure aren't expensive. Hope this can help someone.
That will be simple.
I just started a worm bin about 1-1/2 months ago. 
. I am currently using worms for composting and have that exact Rubbermaid Tub for my worms, however, I realized that I needed to create a new crate on top and didn't know exactly how I should go about it. Now, I do. If I had seen this website when I first started searching the web for worm composting I would have saved tons of research time and effort. Better late than never. Don't know when this was posted but I'm pleased as punch I have seen it. Here's to you! 