Once you have your eggs:

1. Go to the location you'd like to promote and hide the eggs. Simply "rez" them (drag it from your inventory to the ground) and then move each egg to the place you would like it to stay.
2. Make sure this egg has the correct group tag for your land or it will fail to work when you leave the sim. 
   
3. Drop a parcel landmark onto one of your eggs so it can be clicked from http://slegghunt.com (You only need to do this once per parcel)  Please DO NOT LANDMARK THE EXACT LOCATION OF THE EGG, just use a general LM for that parcel. It is best to generate a new parcel landmark from the World->Create Landmark Here menu.
4. You may optionally drop a prize into each egg to be given out to those who find it. Instant win cash prizes are active for all eggs and paid from The Great Grid-wide Easter Egg Hunt account.

Note: Any egg containing a landmark, script, texture, notecard or any other object will give this object to any hunter who finds it - please do not put no-copy items into an egg unless you intend to lose it to the first finder.