I really agree with LoveMamaNetworking. Each baby takes time to adjust to the world and each one tends to run a little one way or the other naturally. My 3rd girl is a July baby (Let's hear it for Cancerians!). I loved the lightweight sleepers -- either the long sleeve w/feet kind or the nightgowns with an elastic bottom. She'd typically wear a short sleeve onesie and a light sleeper. We did swaddle for the first, like, month or so. She was comfy when covered and still, at 19, tends to feel chilled easily. My October baby, though, has always run hot; the "sweats in her sleep" kind of kid. Each one is so different!
BTW -- I agree you need to be aware of drafts and A/C. They both made my little baby very uncomfortable unless we added a blanket. Gotta figure they're initially used to your body temperature of a very consistent, no draft, almost 100 degrees! And I, too, used to go by the "one layer more than you're wearing" rule. Seemed to work in our house!
To leave the hospital, each of my girls wore a special outfit provided by a wonderful aunt: a onesie, tights (socks just don't stay on new feet!), booties, a hat, sweater and beautiful blanket. The summer outfit was lightweight; the fall one, a little warmer. My sisters (the aunts) thought that leaving the hospital would be the first time a child really went into the world and she should be dressed for the occasion!
Very best wishes for you! There's nothing as scary and as wonderful as bringing your new little one home. How exciting!