We are traveling from TLV on KLM then onto Houston on United Airlines. Do we need assistance to do this - is it easy?
Amsterdam Schiphol Airport is extremely pleasant and very well-organised.
I'm not sure why you think you might need assistance to make the connection? Yes, it is easy. Just follow the 'connections' signs (signage is in English as well as Dutch, of course). Unless you have mobility difficulties I see no reason why you should need any assistance.
You will be connecting from a non-Schengen flight to another non-Schengen fight so will not need to formally enter the Netherlands. You will of course go through a document check and security scanning of yourself and your cabin bags, as is normal whenever one makes flight connections at any airport anywhere.
This official airport page gives you lots of information about making transfers at Schiphol:
https://www.schiphol.nl/en/transfers/
and KLM has its own information page about connecting at Schiphol:
https://www.klm.com/travel/gb_en/prepare_for_travel/at_the_airport/connections/index.htm
Browse through the airport maps here before your flight so that you have an idea of the airport layout:
https://www.schiphol.nl/en/page/airport-maps/
Making a connection at Schiphol really is very easy. :-)
Cathy