Organizing takes time and you need to be around a lot to keep the threads bumped for it to be successful.
You need to set dates....about 7-10 days for sign-ups and the same for mailing.
People PM you their info.
You want to set a minimum limit on $$ to spend.
You might want people to say things they like or don't like and allergies.
I do a random draw for names.
PM them to people. Start the send/recieved thread. Keep it bumped, especially until things start moving.
Then the hard part. When the mail by date comes and people haven't mailed

Then you have to get tough and get them moving so no one is left out.
I usually hope that all are received by 2 weeks after the mail-by date.......this is all a long process
If it is a large exchange, you will have nonsenders....almost assured

I have 2 right now in the recipe exchange.
I get some nice, generous people to be "elves" for this reason. They volunteer to send in the case that someone doesn't follow through.
I always am the first elf (one of the obligations, IMO, of hosting).
I am keeper of the nonsender list.....and it is long!
If someone decides to host this, let me know and I will send it to you.
But....if no one wants to, there is a Disney Christmas Only exchange that has sign-ups through tomorrow.....that is anything Disney and related to Christmas.
And the next "color" exchange up is "holiday", so that is related too.
I am keeping busy with the Yankee Candle Holiday exchange that is taking sign-ups now.
And don't forget the annual ornament exchange will be starting soon too.....plenty to keep us all busy.
Good luck.