How to make a raised garden bed

I bought pre-cut  cedar boards to make this quicker and easier. I used 1inch wide by 8 inch tall in 4foot and 6 foot lengths. I will be making two, 4foot by 4 foot beds. And two, 4 foot by 6 foot beds. And to secure the corners together. I bought two 8 foot lengths of 2"x2 inch. I cut them down to 12 inch long.Total cost for lumber about $100.00 Us. And screws about $5.00

This first bed will be used to plant potatoes. The way I am doing this bed, I hope will help with both too much water and not enough.  It is called the Hugelkultur way to garden. Where you dig down a bit and add wood. The wood will act like a sponge. and wick it into the roots of the plant. And by it being raised. The water will not stay in the bed to flood the plants. When we have excessive rain. So I hope this combo. Will make the water level just right. 
 Part 1

Part 2