There are SO many choices for food! I'm sure some others on this forum can give you reasons why you should go with one food over another. My general advice is make sure you get a puppy food that's specified for large breeds.
You're going to hear a lot of crap about protein - feeding too much or too little, etc. Ignore it. Protein does not cause improper growth in large or giant breed dogs.
It's not as important with large breeds, but I'd probably still follow these guidelines - calcium between 1-1.5%, phosphorous between .08-1%. A study done by Michigan State a while back showed increased risk of diseases such as pano and HoD, as well as knuckling, in puppies that were fed higher amounts of calcium.
I'd also caution you to keep your puppy lean. Everyone thinks a fat roly poly puppy is cute - until that puppy turns into an obese adult with hip dysplasia. You should always be able to see a waist line and preferably see/feel the last 2-3 ribs of your puppy with ease. Spine and hip bones shouldn't be prominent.
With all of that out of the way, PLENTY of kibbles fit those guidelines. I feed Earthborn and really like the brand. Acana, Fromm and Orijen also have great kibbles.
If you want to look at other brands or have a price point, I'd encourage you to look for a food with a protein meal as at least 2 of the top 3 ingredients (chicken meal, turkey meal, salmon meal, etc.). Avoid fillers like corn. Don't buy anything that says 'by-products' in the ingredients.
If you have any questions about specific kibbles, please feel free to come back and ask!