I did use the dek blocks for my Home Depot kit. We actually did sink them about half way into the ground. We used 4x4's to level out the deck. Get some string and a string level.
The 4x4 just sit ontop of the dek block and your beams sit ontop of the 4x4's. The weight and span of the deck will keep them in place Toe nail in from the beam to the 4x4.
Now this isn't probably the best way to build a deck, but it was easier and less expensive than all the contrete and renting a post digger. Plus my deck isn't that high off the ground - just 2' at the highest point.
I wrote about it on my blog here http://easydeck.blogspot.com/