Fireraven9
Come my spade. There is no ancient gentlemen but gardeners, ditchers, and grave-makers; they hold up Adam's profession. - Shakespeare, Hamlet V,i

There is a superb book on raised bed gardening that will answer every single question you have. It's called, "How to grow more food in less space, with less work, etc., than you ever thought possible." The title is approximate but close. The author is John Jeavons, the father of the "Bio-dynamic/French Intensive" school of raised bed gardening. It's an extremely well written and information dense 8x11 paperback. Basically what he shows first off is what amendments to lay over the soil followed by how to double dig it with hand tools. Next he gives instruction on how to plant seeds and seedlings for complete coverage of the soil and even specifies the distances between the different types of plants. I use his methods and have for years, although I am by no means a purist in organic gardening. For example, I use a Honda Harmony mini-rototiller for very fast bed preparation. I use Miracle Grow and other spray over fertilizers for fast easy fertilization. But I manure the beds each time I plant and till in the garden waste and lots of organic materials as well.

For more information on this you can visit my website where I've assembled lots of links on this and other subjects.

Bob

The current thinking is to put ammendements such as compost, etc, in a layer over the top of the soil and NEVER disturb it. I assume it might be necessary to a certaian point in the first season to get grass and weed cleared.