How long do I wait before using saw dust chips?

I am transforming a 1/2 acre area into a permaculture garden. The soil is sandy loam, with only a small amount of dirt. I have been bringing in fresh loads of hardwood sawdust. This year, I plan to plant a small garden.

I have a few questions:

How long should I wait before using the wood chips?
Should I keep the wood chips in a pile, or spread them out in the area where I intend to create the garden?
What type of bio tea (mycelium) would you recommend to help break down the wood chips faster?  Please be specific and provide links if needed.

Thank you in advance for any of your insightful responses.

Spread them in the area where you want to plant, and inoculate with wine cap (Stropharia) or oyster (Pleurotus) spawn. Both of these mushroom types tend to like hardwoods.  You don't really need to wait, but time will only improve things.

When it's planting time, just pull back the chip layer a little around where you're putting seeds or seedlings. Don't dig it into the soil, but leave it on top.