The Art of doing stuff explains how to harden off your seedling before transplanting outdoors. I know many folks lose their seedlings after sowing them indoors by rushing to get them into the garden. This article explains why you can not do that and how to get the seedlings ready to go in the garden.

http://www.theartofdoingstuff.com/the-final-step-for-your-home-grown-vegetable-seedlings/