I'm new to growing in general, but I've been running an eb and flow system. Done a lot of research on the forums, and my plants are doing lovely, so I'll see what I can do to help. I think a lot of the more experienced growers are just tired of answering the same questions over and over again.
1. What light cycle should I have my seedling growing in?
Same as with dirt, either 18/6 or 24/0. Some people say the plant needs the dark period to grow roots and take a break from all that growing, others say it can grow as long as there's light. I do 18/6, since it doesn't seem to make too much of a difference, and saves a little on the power bill.
2. When do I add nutrients? Are the nutrient tablets the set came w/ okay?
Most people say after 2 or 3 weeks. I've also heard after the 3rd or 4th node. I didn't know any better, and added nutes right away. As long as you do it slowly, and back off if they start to burn, they seem fine. I don't know anything about tablets. I'm using GH's flora series. Lots of people seem to like it, and it's relatively cheap.
3. What should my water's pH be at?
5.8-6.3 I have to adjust mine every other day to keep the reservoir there, but I think that's the rockwool's fault, and your system probably won't have that problem. I don't notice a difference even when it climbs up to 7.4, but I'm going with the general consensus on this one.
4. Anything else I should know as I journey into this adventure with no map?
Lots. There seem to be a million little things that go into growing weed, and at least a few more when you put hydro into the equation, but when it boils down to it... it is a weed. It's pretty hard to mess up as long as you check on your plants often and listen to what they're trying to tell you. You can pretty much find anything you ever want to know on these forums(the search function is awesome when it's working). I've run into several problems, but none have been disastrous. Check out my journal if wanna see the trials of a total noob jumping in head first.