I usually breast the bird as soon as I get home, then throw it in a brine. If I'm eating it that night I'll throw it in a marinade when I get home from work, if not I'll leave it in the brine until that evening then marinade.
Brine for at least 6 hours.
Marinate for at least an hour (Olive Oil and Worcestershire Sauce)
Grill until medium.
It's been a winner every time for me. Good luck!