1- can you work for more than one agency?
yes, you can work for as many agencies as you have time to sign up for. you will probably end up settling for one or two that you really like. be aware that you can be cancelled even if you are on the schedule. generally they must give you 2 hours notice, and if census drops, you are the first to be asked to go home. so if you need a guarenteed schedule and income, it may not be for you, but if you can be flexible, you can make a lot of money, meet lots of new folks, and quickly learn which hospitals you want to stay away from!
2- if you are not a traveler, do you have to sign a contract (ie, what if you don't like the places they send you to?)
with an agency, you are strictly per diem, so if you don't like a place, you never have to go back. some agencies offer "local contracts" which means you will still make good money, but generally will not have travel or housing allowances like a traveler, but you have a committment for 13 weeks if you like. there are advantages and disadvantages to both. you just have to decide.
3- for the places that advertise 'daily pay', is that really so?
i think these places will pay daily, but there is a little more paper work involved for you, and you may have to go to the company to be paid. some places say daily pay, but they really mean they can pay you daily in an emergency, but would rather not because of the extra paperwork they must complete. most pay weekly, and that has been enough for me.
4-i'm in ny. does anyone recommend (or not recommend) any agencies? can't help you there. maybe go to the ny section and ask.