I'm new to the whole hydroponics thing. Well the whole gardening thing really. I am in the process of setting up my own Recirculating DWC system. My seedlings have already been started and want to get the system up and running before I have to transplant them. I have a few questions for you guys!

I already bought the growing containers I need, Which are 11 18 gallon totes and 14 5 gallon buckets.

The plants I have are rosemary, thyme, basil, cilantro, lettuce, kale, romaine lettuce, cherry tomato, carrots, onions, Marvel peas and bell pepper.
Inside the 5 gallon buckets I plane to put the bigger and taller plants in, such as the tomatoes and peppers, one per bucket.
The smaller plants like the lettuces and herbs will go inside the 18 gallon totes, 6 plants per tote.

1)Will 6 plants per tote be okay?
2)How many GPH of water does each plant need?
3)What is the flow rate each plant need?
4)What size reservoir?
5)How big a pump?
6)How big do the net pots need to be for each plant?
7)How big does each of the plants root systems get?
8)What should the water level be in each bucket and tote?
9)Where should the return line hole be on the bucket and totes?

I've read that hair should be pumped into the water so the roots can get oxygen.
10)Should the airstones be in the reservoir or inside each of the grow containers?
11)How much air needs to be supplied?
12)What size pump is required?

I believe those are all the questions I have. If I think of anymore I'll let you know. Any help is very much appreciated! :)

Regarding your system, you should probably choose between green leafy crops and fruiting crops, and not try to grow both in the same system. They do best with different nutrient mixtures and different artificial lights, if your system will be inside. It's easier to grow leafy crops; you might start with those first. If you want to do both at once, then built two separate systems.

As grizzman stated, you are asking a multitude of (all good), but may want to slow down a bit and re-evaluate your grow and the space you have available.

I say that in light of the fact that I tend to over load the system as well!

Pics?

1. The number of plants per tote depends on a few factors. Size of mature plant is the most important, although you can do much denser if you want to do an extended harvest of young greens. I'm growing 30 basil plants in a 15 gallon DWC with a 150w HPS and 2 42w (6400k) CFL. I'm using 2" net cups, spaced like a cloner.
2. Varies greatly by plant size, higher with larger plants. Add air stones in to every bucket and tub, as well as the reservoir.
3. This is the same question as 2, but I'll take this time to mention that all of your setup needs to be sterile before you use it, and all water bins, lids, and pipes need to be completely opaque. If it's translucent (any light gets through), you'll likely have a downhill battle with algae and/or root rot. Spray-paint it black then white, or return it and buy opaque stuff. Seriously.
4. Someone covered this, but you also have to keep in mind just how much water will be used on a daily basis. Having a reservoir that is the volume of the full system might not last for a whole day when your plants grow up. You need to maintain a high enough level to stay above the pump, and also to not cause the water to be toxic. Plants don't use nutrients and water at the same rates, so over time your solution will either increase or decrease in concentration. At high concentrations, some plants will die. Think of it like this, we (mammals) need salt to live. If we're stranded on the ocean, we will die of thirst because the water is too salty for us to drink. It would dry us out just like too-strong nutrients will starve and kill a plant.
5. Your pump just depends on your target flow rate. I've done 6 outdoor top-feed tomato plants, and a pond pump was more than I needed. I'm doing DWC now, but not recirculating, and I don't have relevant experience.
6. Net pot size depends on plant size. I'm using 2" for basil, but I would go for 4-6" for larger plants. The most important consideration is that you are able to block light to the roots with hydroton and maintain plant stability. e.g. basil would do just as well in a 6" pot as in a 2", but tomatoes in a 2" pot would destroy the pot and likely fall over.
7. Varies by plant, but they will grow to be as big as they need to be. In a DWC, don't worry about how big they will get. You'll be fine. You do need to make sure that the roots don't grow in to your pipes (they will surely try) and block the drainage. Think flood. That's another reason to not try to have everything on one system. A single failure could kill your entire crop.
8. For baby plants without roots outside of the net pots like clones and new transplants, water needs to be high enough to keep the plants wet. If you're starting seeds or clones in rockwool, put a layer of hydroton in the bottom of the net pots, then put in the rockwool. Fill beside rockwool cubes with hydroton. Water should touch hydroton, but not rockwool. When first roots start to hang down, water level should be lowered to a bit below the net pot bottom. Leave a bit more space if you're crazy enough to not put in an airline and stone to each bucket.
9. Both/All.
10. 1 stone in each bucket/reservoir will be enough, but some people will say that more is better. There is a saturation point where no more oxygen can be in the water, and it depends on temperature (colder = more dissolved oxygen).
11. The pump needs to put out enough for each stone, so you'll need a strong pump (or a few weaker ones). Don't quote me on this, but a rough estimate might be about 10w per air stone. You'll also need to take in to account the length of air tubing (longer requires higher pressure) and depth of water (deeper requires higher pressure). Separate pumps will help when one fails as well (and it will).
Hope that helps!

I've found the wire tomato cages do a great job when fashioned upside down with the base bent to accommodate the reservoirs.

I've seen some really neat wire and string set-ups as well, but plenty of bracing is needed to prevent sag.

Read and watch everything you can and then begin putting it to use.

I have found that using a journal in just about every technical hobby has been a key to success.

Speaking of success...best of success to you!