Another Type Of Hoop

So the time has come, it seems, to stop thinking about planting seeds and really plant them.  The hoops are in place.  Once the seeds are planted and the soil watered, I'll cover the beds with row cloth.  It will let in the sun and some moisture while keeping out birds and squirrels (hopefully).  It should also protect the delicate new plants from the heavy rains which seem to fall frequently.
The half barrel is for potatoes.  I'm a little uncertain about the potatoes.  It seems that in order to grow potatoes one must first have potatoes which are then stuck in the dirt.  Go figure.
I need to learn about compost -- how and when to use it and how to acquire it.  I know that the town in which we live will provide compost but I'd kind of like to make my own instead of throwing the stuff of which compost is made into the trash.
This is all new to me and I'd appreciate your suggestions and guidance.
I'll keep you posted.