We may move from being 'tiel petsitters to 'teil owners...help me with nippiness?

OK, so my sister was having me watch her birds but she really wants to give them to me. My husband finally won over the bird's trust and he really loves the idea as well. Stewie is the male and Chicken is the female.

We've had them for four days now. On the second day Stewie was letting me scratch his head, and on the third day Chicken did as well. On the third day I took both of them out for some shoulder time. They seem to be doing well despite their challenges. My sister had a baby a year ago and I'm afraid the birds haven't been outside the cage very much at all. So considering they are in a new home with lots of noisy kiddos they seem pretty happy. They live in my office (no kids allowed in there) and we keep a baby gate on the door so the kids can talk to the birds from the doorway.

I guess if we are considering keeping the birds I'd like to work more with them with having them be happy so I have some questions:

My sister gave me a bag of bird seed. I'd like to offer them fruits and veggies and other things besides just a seed diet-where's the best place to start? Chicken had some nibbles from my graham cracker. We are always feeding our kids all sorts of fruits and veggies so to put a bit aside for the 'tiels should be easy-how much wil two eat in a day?

Stewie keeps trying to nip at my husband and me when he suspescts he's going back in the cage and sometimes when he's put his head down to be scratched...my husband found the clever solution of putting him from shoulder to hand while in another room then walking into the cage room and he went in without a fuss then. Chicken hardly ever nips and is very quiet, calm, and happy.

It seems they startle at unexpected high movements when on my shoulders and take off. They are getting to know the house so they fly around quite a bit looking for curtain rods. The kids just stare fascinated at the spectacle. Anyway, after they land on a rod we get a chair and get the bird down and they seem fine. Just checking if that's the normal behavior...

Sometimes they get shaky on my shoulders but I figure they are still getting used to the place, it's probably nervousness.

When will I know if they need beaks or nails tripped?
in the cage there is a red thing my sister has for them to sharpen their beaks and they use it all the time. There is also a sandpaper-covered perch which I guess is for their nails?

Any recommended websites or books on tiels?

Thanks!

biting: when they bite you can "ladder" them. that is, when they bite, have them step up, then step up again, and again, about 9 times in a "laddering" motion. this shows them your in charge and that when they bite they have to work.
veggies and fruit: just offer them to him with his pellets or in a separate food dish.
flying: you should start recall training them or clip their wings. if not properly trained, flighted birds can be very bossy.
Grooming: you will know when their nails need to be trimmed when they get long and start to curve downward. beaks don't usually need to be trimmed, unless they are very overgrown. when they get that long, you'll be able to tell. try switching out the sand paper perch for a concrete perch, sand paper can irritate their feet. The red thing could be a dyed cuttle bone or mineral block, they chew on it to get nutrients and file their beak.
It looks like you found your perfect bird good luck!

Congrats!! Tiels are such sweet birds!! Ann gave you some really good advice. Good luck. I am sure as they adjust and get to know you, they will settle in really good. It just takes a little time for them to feel comfortable.

Will they generally keep getting friendlier as we keep handling them?

There is a forum dedicated to just cockatiels, and it's called talkcockatiels.com

Welcome the this forum...

Cockatiels are wonderful birds to have around! IF you were to keep them flighted, make sure ceiling fans isn't on and the doors is always closed so they won't fly out, you guys should make it a habit to do so. IF you provide mineral block and cuttle bone, very rare you would ever need to trim their beaks. Get concrete perches as it will help keep their beak and nails trimmed as well. Depends on their color, you can see the blood vessel if they have lighter colored nails. It's actually best to have a professional to show you how it is done cause you can cause them to bleed. Simple items most people have in their house to help stop bleeding is corn starch and flour. Usually when it's a pair, if not taken out in a long periods of time, it's not easy to train them down without doing the clipping. One of my males was mean at one point but now days I can pick him up without him attacking me. I've raised Tiels for many years. Good luck with them and welcome to the forum!