I have a NA 6.2, so I'm not sure if a turbo changes any of the frequencies, but here's a list of my maintenance schedule:
1. Every 1500-2000 miles I change the oil. This may seem excessive, but I started doing this after I changed the oil sooner than normal by accident and noticed how much cooler the engine ran. I personally use GM 15w40 and a GM oil filter.
2. Change out your fuel filter(s)- I have two on my 83- yearly. Diesel fuel is full of crap and a bad batch of diesel can clog a filter in a hurry. This is something to keep in mind if you ever have fuel delivery trouble.
3. Air is a diesel's best friend. The better the air supply the better your truck will run. On a gasser you can get away with a slightly dirty filter. With a diesel, the first hint of dirt build-up on the filter element means it's time for a replacement. On average I change out my air filter yearly, but I don't wheel the truck(it's a 2WD 1/2 ton). If you wheel you rig I'll bet you could be changing the air filter out once a month or more. Some guys swear by K&Ns but I have yet to splurge on one(they cost $90 up here) so I can't tell you how much of a difference they make.
4. Get used to the fact that you should be using a quality diesel fuel conditioner. Diesel used to be full of sulphur and this helped lubricate key injection components. Unfortunately, sulphur turns to poison when it's burnt so fuel companies were forced to take it out of the mix. So now we have diesel fuel that's healthy for the environment but unhealthy for your truck. To keep your injector pump and injectors properly lubed, you should use a conditioner. Good conditioners also include some fuel system cleaners. Stanadyne probably has the best conditioner on the market, but any brand is better than none at all.
There's the basics. I don't think I missed anything but my wife and I are on our second bottle of wine already(tough day at work/forums/images/icons/tongue.gif) so my mind is a wee bit blurry.
I think it might be worth mentioning that 6.5 turbos have a rep for losing their injector pumps. I'm sure a lot of it has to do with people not using conditioner. GM has recognized this problem and for certain model years they have extended the warranty on injection pumps to 7 years. That's in Canada, though- I can't speak for the US.
That's about all I can think of for now. I hope my half-drunken rambling hasn't bored you/forums/images/icons/wink.gif. If you have any more questions, post them and I'll answer them if I can....