Step 1: Tools and supplies
Circular/ table saw - not really needed if you have a lumber yard that will cut to size for you
Plywood- preferably 3/4 in thick. I used 1/2 in and it worked fine though
metal racks- For the shelves, I went to a local recycling center. They were nice enough to let me dig through their pile of appliances and random metal. There I found 5 racks out of old ovens and had them cut down so they were all similar sizes. they sold me all five for a $1 so I couldn't complain with that.
wall plug in
wire- i used 12 guage, probably could use something smaller
some type of closing mechanism- I took a metal clamp off an old grill that works great to hold the door closed
small fan - You can usually fine these for cheap at any thrift store
wire mesh- I live in an area where there are a lot of bugs, therefore I put mesh on the air holes to keep them out
Step 2: Cut wood panels
Step 3: Assemble box
Step 4: Wire light sockets
The only experience I had with wiring was from high school when I took home maintenance, which is basically none. I asked my local hardware stores if they had any tips and they all said they couldn't tell me anything for liability purposes. After looking around for tips online, I figured that would try using a daisy chain pattern.
This is a pretty basic wiring set up. Having little to no experience in this I will describe it the best I can. Starting from the wall plug in, connect the black and white wires from the plug in to short pieces of black and white wires respectively. For the rest of this I'll just talk about one wire but it's the same for both the white and black. To the short wire you connected to the plug in, using a twist on wire connector connect two short wires. One of these will go to your first light socket, the other use another twist on wire connector to connect 2 more wires. One of these goes to your second light socket and the other goes to the third.
I'm not good at describing this kind of thing but I hope the pictures help.
Step 5: Put it all together
Place the lights and fan in the base of the box. I use 100W light bulbs and when I did a test run without the shelves the box held at 125 degrees Fahrenheit . I placed shelved 6" apart but you could do closer for more shelves. Right now I have watermelon and pears in mine. most fruits from what I have heard will take 24+ hours but I'm still experimenting. Good luck and enjoy!