Terminal 7

You have just enough time to do that. Take Airtrain (the station is located across Terminal 7)on track 1 for one stop to Terminal 8.
JFK_E

You have enough time.
You clear customs and immigration at Terminal 7.
You can transfer your bags at T7, Iberia connecting flights counter or you can take them with you to T8 and check then in with AA.
JFK_E

1. The taxi stand is right across the street on the first floor(arrivals level)
2. Not the yellow cab. Those are private taxi services that a passenger self arranges( no taxi line to wait ).
3. The yellow cab drivers will be more than happy to take you there since it is a long distance for them. By the law they are not allowed to say "No" to ANY destination requested by their customer.
4. The yellow cab will run on the meter and going to NJ area is a different zone(could be very costly). On estimate will cost you on yellow cab somewhere around $150+. Most of the yellow cabs accept credit cards(you have to request one from the taxi dispatcher at the taxi stand) so no need to carry cash.

That said, I will suggest you to take a private car to your destination. Once you arrive look for self-service Ground transportation phones. There (at no cost) you can call a private car by dialing either 31 or 34. The price will be given to you prior to arranging the service. The cars arrive usually within 10-15 min .
Here are the web sites of those two car services:
http://www.dial7.com/
http://www.carmellimo.com/
You can even get a quote on you ride at their web sites.

JFK_E

Either terminal(1 or 7) is good for that purpose.
JFK_E

Hi Liz,
The time is enough to do that as long as your Iberia flight is on time. When you land you pass through immigration, pick up your bags and pass customs. Then you can look for Iberia representative and asked them where you can recheck you bags for transfer.
Once out of T7, cross the streets and go upstairs to the Airtrain Station. Take ANY train on track 2 for one stop. At T5 go to the second floor ; if you don't have a boarding pass, get one from Jet Blue counter and look for security checkpoint where you go to the gates.

JFK_E