I haven't had a Wolfhound but I've had 8 Pyrenean Mountain dogs, 4 of them large males. I also had a male Anatolian Shepherd dog. Not quite Wolfhound height but still massive dogs. We very nearly got a Wolfhound when I was a kid but ended up with a Pyrie instead.
When you say you want a giant breed you always get naysayers, for some reason it really irritates people that you want a dog bigger than a retriever.
Anyway, first piece of advice is to make sure your garden fence is adequate. We have 5ft chain link and concrete posts with 6ft wooden panels a few inches outside it and a tall metal gate with signs up. Even if your dog is not an escapologist they can knock out a fence panel so you need mesh inside it.
Secondly, with regard to giant breed puppies the golden rule is no stairs and no jumping. Puppy gates everywhere you can. You need to lift them in and out of your car initially but as they grow you can switch to lifting front end then back end.
Food - be aware of the risk of bloat so no exercise for one hour before or after meals and continue to feed 3 or 4 meals as adults if you can; it is safer than one or two large meals. Good quality large breed food is best.
Exercise - not too much initially because of the fast growth rate. Several short walks is better for growing pups than one long walk. Free running is good but they also need a lot of rest periods.
With regard to training, right from the start you need to be able to handle their toys and food. So sit on the floor and put your hands in the food bowl when your young puppy is eating. Add a piece of kibble, take a piece out. Turn the bowl. They need to get used to this early. Same with toys; offer a toy, take a toy away. All this is important. You cannot have reactive guarding with a giant, they have to trust you and you have to trust them.
Giant dogs, particularly as pups, have absolutely no concept of their size or strength so lead training is massively challenging, even if you go to puppy class. They pull like crazy, jump up and bite the lead. They do grow out of it but you have to be prepared that even a 4 month old giant is bigger than a Retriever and can pull you over.
Good luck. You won't regret your decision. Giant breed dos are absolutely amazing. So loving, just wonderful to be around. You probably wont stop at one, they are addictive (we had three PMD in a normal 3 bed semi).
I'll probably think of other stuff to say but if you think of any specific questions just ask.