You can take enough made up for the flight and journey, but you have to taste it. You should also check with the airline your flying with in case there are any additional rules.
yes b.milk, milk and formula, you can take w/you as much as you need and you won't even be asked to taste it at the airport!
other juices go under the 3-1-1 rule, which is 3 oz of liquids, in 1 quart size bag, only 1 bag is allowed.
Yes, they are allowed but you have to bring it in powder form unopened and either buy water at the airport past security or just ask for some on the plane or bring in the premixed formula unopened. food is allowed as long as it is unopened in its original container. (only baby food though)
Ring your airline - they will tell you. I'm a frequent traveller and I do remember that airlines usually make allowances for baby food. If the baby drinks formula and you really need to heat up your own water (best bring your own with the formula in separate container), the plane should have a microwave (be careful of hot spots!). Otherwise, just carry some jars of baby food/compote etc. It's easy. Don't sweat over it. My baby has been flying since she was a few weeks old (she's been to 8 cities in 9 months).
I flew with my son, and I had two bottles made up and then some water and powder just in case. I would say that the ready to feeds would be the simplest, as they can be left at room temp and not spoil like a bottle can. As for food, if you need it, bring along a couple of jars.
Here is the link I followed:
http://www.tsa.gov/travelers/airtravel/children/formula.shtm
Edit: this in response to the one above me. You do not have to taste anything. Although at one airport they did test my bottles with the formula in them.
Your best bet is to call ahead and find out from the airport that you'll be departing from. You shouldn't have a problem bringing milk for the baby onboard, although I know for awhile that some people weren't allowing it.