Most plants prefer a neutral level of about 6 or 7 on the scale. This site will tell you much more about that subject. In the meantime, here are some improvements you can make yourself. To increase soil alkalinity, add some hydrated lime. To increase soil acidity, add sulphur.
Peat moss boosts acidity, organic matter, and moisture at the same time.
To raise the level of nutrients in the soil, add fertilisers containing nitrogen, potassium and phosphorus. Always apply as directed by manufacturers. To make digging easier you can rent a rototiller. Depending on the size of the job, there is the double digging method in which you work your way across the bed, moving 1 foot trenches of soil at a time. Dig a trench about 1 foot deep, putting the dirt in a wheelbarrow.