How early do you start plants in AG for the summer?

I second maskedsonnet reply. Usually for cherry tomatoes in 30 days you can have flowers. Peppers take longer usually just because they seem to germinate slower for me. After 10-14 days I transplant to 32oz or 44oz cups with potting soil. within 30-45 days of planting in the seed starter they can be outside and growing. Back up your last frost date by 30-45 days and start then. I transplant mine to cups because the roots will get very tangled in the seed starter tray if the plants get to big. I am starting stuff this weekend for the summer and my last frost date is may10th. I may be jumping the gun abit . 

The official AG blog says (or used to say) that you should harden off your transplants before moving them outdoors.

I ignore this advice, and am very blase about transplanting AG seedlings. I just remove the seedling from the deck, and stick it in a pot filled with Miracle-Gro Potting Mix. Then I put the pot on the display rack pictured in my avatar, and water the heck out of the plant for about three days. That way the seedlings transition well from growing in water to growing in soil.

Probably horticulturists and serious gardeners all cringe at my rough handling of the poor transplants, but they do okay. The potting mix has fertilizer in it, which is probably the secret of my success. That, and the plants' will to live.

I also don't bother hardening off seedlings; they just go from the AG seed starter directly to the raised beds.  I almost waited too long this year; I had a "root overgrowth" problem and it really turned me off the seed starter trays.  I have much better results by starting seeds in the old-fashioned seed-starter trays filled with potting soil under a grow light.  (Y'all know I am a "lazy gardener."  )

Trial by fire for the seedlings! lol, I will try the same then