I dont see why it would hurt to do some worms. I mean i would add some organic matter for them to bed in. Im no expert but I have 2 nice bins indoors. I dont even use a drainage system. Its all about trial and error. I started out with less than 2 dozen worms in march and i bet i have close to 3 to 5 thousand. We have a lot of RED Clay here in NC. Im going to try to save the castings and put them in this spring. Ill till under everything this fall to add Lime.

Thanks for the encouragement. I'm going to remove
the dirt tomorrow and put many layers of cardboard
underneath to insulate from cold. I might even have
a second insulated board.

Not sure what to use around the sides? I thought of
bunching up newspaper and then, wrapping it with cardboard?

Should I tilt the pool and drill a hole right at the base?

I had a bin in the house last winter. Picked up worms from
around the yard. I found out later that most of the worms
were NOT red wigglers. They did not survive.

I'd really like to learn more before I go into this in a
big way. Karen zone 7a

Do some reading on this forum and others. Two others I visit often are thegardenforums.org and vermicomposters.ning.com. There are a lot of good questions and answers and a lot of good people on all three. You'll find you can learn all basics you need to get started by looking at people's questions and answers.

I agree with mma_fanatic976 about trial and error. The best thing you can do is to get to know where people have found success and where people have gone wrong and try to apply to your situation. Every worm bin will be a little different because of bedding, food items, moisture, humidity, temperature, etc. These forums are also helpful if you run into trouble. A lot of people eager to throw in their two cents of advice.

from my own experiences I think you should be able to do ok with that pool, just be aware that feeding will slow down in the lower temps so they won't require as much food nor will they produce as much castings. what may be difficult is keeping the moisture level in range with such a large surface area. It'll likely require some pretty good monitoring at least til you get a feel for it. Oh and put some of that dirt back in with your organic stuff it helps worms digestion.