I just copied this from Kevin's post last year. Didn't see any reason to re-invent the wheel, since Kev already laid out everything, might as well use it again! (Thanks PVB for posting the link!)
"Here is the final parade information-
Thursday I will pick up all our parade ribbons at the registration desk. There will be no need for anyone to ask the DC staff if they (as an individual) are registered with the parade. Please do not try to pick up your parade ribbon yourself as it will create unnecessary confusion.
I will hand out parade ribbons to everyone on the current sign up list in this thread Saturday morning. There will only be two extra spots for any last minute commers. I will absolutely hate having to turn anyone away- but unfortunately "them's the breaks".
This next part is direct from the DC parade staff:
----------------------------------------------------------
Where and When To Be Parade Morning, Saturday 9/5-
Woodruff Park, at Peachtree Street and Auburn Avenue about 4.5 blocks south of the Hyatt Regency front entrance is the place to be.
Vehicles/floats and their drivers must be at the park NO LATER THAN 9AM. Parade staff will direct you into place and will signal you when it's time to move up to Peachtree Street. The earlier you can get to the park, the better.
Marchers must be at the park NO LATER THAN 9:30AM. We'll have signs designating each parade section. Sections will be lined up in the order in which they step off onto Peachtree. Unless your section has been given a specific location to gather, please follow the directions of parade staff. Once we begin to move everyone onto Peachtree, if your group has a vehicle in the parade, please move into position with it as it approaches.
We have lots of vehicles in the parade this year - some of them are really big - and, so far, over 2600 people planning to march. It's critical that we have room to manouver and get them in place before the majority of marchers arrive.
Once we get rolling, if it seems like we're yelling, screaming or 'in your face', please don't think it's because we're a bunch of rude or angry people. It's flat out loud at the park and our bullhorns and voices don't always carry over the conversations and general noise. Please stay as focused as possible and when you hear your section or vehicle called, be ready to move!
And for your safety: Drivers, please stay with your vehicles and Marchers please stay on the sidewalks until you are called forward. The streets are not blocked from regular traffic, including buses, until just before 10AM. Not optimal but what we get.
Parade Staff Hours at Woodruff Park:
I usually get there around 7:30AM. Staff rolls in by 8AM. We'll be there for you!
The Parade Route
For returning participants, it's the same as last year. For our new members, it starts on Peachtree Street at Woodruff Park, continuing north to the Hyatt Regency, turning onto Baker Street, then continuing to Courtland where the parade ends at the Marriott's back entrance. The route is about 1/2 mile long on mostly level city streets.
A Few Very Important Reminders
Weapons policy: All weapons carried in the parade - toy, prop or otherwise - must comply with the Dragon*Con Weapons Policy. D*C Security approves and peacebonds weapons before they can be carried at con, including all events like the parade. Please take care of this BEFORE Saturday morning because we'd hate to see anything confiscated by the APD or D*C Security at the park.
"Rain or Shine" policy: If it's less than sunny, overcast, drizzling, or intermittent showers are forecast - we march. If it's pouring down rain or there are active thunderstorms and the like - no parade, stay safe and dry. There is no rain date for the parade. If it doesn't happen at 10AM on Saturday morning, it just doesn't happen at all. Now is the time to commence with the "NO RAIN" chanting and dancing.
"Members Only" policy: The only exceptions to this rule are those that I have approved before Saturday morning. Those exceptions are few and far between. As mentioned in a previous message, D*C Security will be doing badge checks this year. If you or a participant in your group, including vehicle drivers, will not have a badge before the showing up at the park on Saturday, PLEASE CONTACT ME VIA PM (dc_parade@dragoncon.org) IF YOU HAVE *NOT* ALREADY SPOKEN DIRECTLY WITH ME ABOUT THIS. We don't want to see anyone kicked from the parade who shouldn't be.
What's Appropriate
Our parade is the very public face of Dragon*Con. Interestingly enough, the majority of the onlookers may not be D*C members but rather the general public (including many, many, many children) who take the time to come and enjoy what we have to show. It's a "politics-free zone." It's subject to the laws and statutes of the city, county, state...you get the picture. It's escorted by the Atlanta Police Department along with D*C Security. It gets generous media attention. We reserve the right to prohibit and immediately remove from the parade any person(s) or thing that is deemed dangerous, obscene, objectional, or engaged in a political action. We're very reasonable though and believe all participants are as well.
Oh yeah, it is extremely appropriate to HAVE FUN in and with the parade!
------------------------------------------------------------------------------
One thing I will add-
PLEASE WATCH THE FOUL LANGUAGE IN FRONT OF THE KIDDIES. We all like to say the "The Sarge is gone! Get the F--- outta here!" line... but let's not okay? Let's behave like professionals and not drop the F bombs in front of the children this year. We have a large crowd to watch us march. "
-------------------------------------------------------------------------------------------------------------------------------------------------------------
Another thing I'd like to add- we are leading the Parade off again this year. It's a tradition I think we'd all like to continue year after year. I know Chris would be very proud of seeing the Colonial Marines march in front of every other costume group...
It's going to be awesome!!
So just smile, wave, thank them for saving your soul with their megaphone if you feel ironically inclined, and then go back to forgetting they exist. 
).