This is what I add to my soil in my garden:

* 1 bag 3.8 cubit feet Peat Moss
* 3 bags Utelite E Soil Builder
* 3 bags Oakdell Organic Compost
* 3 bags Gardner Bloome Soil Building Compost
* 1 bag Humate Soil Conditioner

I put this on in the Spring and again in the fall. I also add untreated grass clippings and fall leaves mulched from the lawn- mower in the fall. This has worked for my size of garden. You can find out more here Andersonsseedandgarden

I will be adding these amendments to our garden and rototill it in to the soil.

In our yard we have about 18,000 square feet of grass. We applied our pre-emergent on the lawn. May is usually when we put it on, we were a little early.
You can find more about this here. AndersonsseedandgardenlawncareYou could also aerate your lawn in the Spring but we do ours in the fall. You would aerate your lawn before putting on the pre-emergent. You can find out more about this here Andersonsseedandgarden

Happy Gardening.

Lindy