What currently are they using at school?
Is the computer required to run certain software?
If so what are the software requirements?

rule of thumb is buy the PC based on the requirement so many people do it the other way round and find out they need better graphic cards more memory etc..

Another thing to consider is why a laptop/notebook why not a desktop. laptops go out of date quicker than desktops (I would say theres like 2-3 years differance in how long before your have to consider buying a new one).

one thing some people say is that a laptop takes more space than a desktop this is not totally true desktop can go in a cubboard and all your need is a wireless keyboard and mouse and use a TV/Mointor type LCD and you wont notice its there.

Laptop (most) can't be used on a lap or carpit they need desk spacehence why there calling them notebooks now days. wireless keyboard mouse can be used any where (except the bathroom;))