Get into a routine right away!
We get a jillion forms to sign during the first week - Emergency Medical forms, rules and procedure forms, permission slips, PTA forms, volunteering, handbooks, pictures, etc!!
This is great time to get your kids into the habit of emptying their backpack as soon as they get home! Have a special place for them to dump their info for you - then when homework starts, they're in the habit and there it will be - no more, "Oh, I forgot about that!"
I keep a copy of a "generic" Emergency Medical form with all those phone numbers I have to look up... That way, I just fill in the names and dates for each kid!
Happy first day of school!!
(sorry I was late today, had a change of heart for my post)