The Guardian recently published an A to Z of ISAs, which did really well until they got to X, where they struggled a bit (X is for Expats).
It’s a good read though and covers the subject of ISAs comprehensively.
Don’t forget, the ISA deadline is midnight on 5th April, so if you wish to take advantage of this year’s allowance and the tax benefits an ISA can offer, you need to invest before then. Of course, a new allowance follows on April 6th, so don’t feel forced to invest in an ISA just for the sake of it.