$50 a year activation fee, this covers everyone who is eligible on your benefits. After that all domestic travel is free, international you pay only taxes.
Spouse/Domestic Parter or Travel Companion (Spouse is free as you are, domestic partners get taxed based on travel from your paycheck and travel companions pay a yield fare per mile per trip)
Parents and Step-parents but no in-laws
Children under the age of 23 are free
Children over 23 pay a yield fare like the travel companion
After a year, you get 8 buddy passes to give to friends and they pay so much per mile (to be honest, it's not that good of a deal anymore. Sometimes, you can find confirmed tickets for close to the same price)
Anywhere Delta or Delta Connection flies.
No real benefit here specific to Skyteam. You can ZED (Zonal Employee Discount) (discounted standby tickets) on over 100 different airlines worldwide. I've traveled from OMA-MCO nonstop on Midwest for $52 each way back in the day so that was nice. I know you can fly LAX-SYD on Qantas for somewhere around $130 I think. So anyway, we get to fly standby on a lot of other airlines for a very low price. And this benefit is extended to everyone on your benefits except travel companions.
All in all, I think I covered the big stuff. I will say however, with Delta, and all the airlines, flying at very high load factors these days, especially this summer, it is not easy to nonrev. Always have a backup or have shifts covered if things go wrong. This summer especially, aircraft are stretched thin and even something small can mess up your plans. One more thing I'll warn you of, don't think that loads are likely to stick days in advance. Loads can change at a moment's notice. It can be as simple as another airline in your airport canceling a flight to their hub for your flight to fill up at the last second. So always expect the worst and hope from the best. I've had some of the best trips in my life thanks to nonreving but I have also had huge headaches and sworn off nonreving forever only to do it again a week later. Either way, have fun!
[Edited 2010-07-18 00:15:00]