Good to use Noscript

Good to use Noscript?

Now after having recurring problems with scareware, just had enough and decided to reboot. Having done virus checks, it does appear that some Trojans are attached to Flash, or Java scripts because they popped up on the AVG logs quite abit. So I'm thinking about adding this No script thing to my Firefox, but will that not allow me to watch videos on Youtube or on other websites?

Are scripts simply just allowing you to watch videos, see pictures etc?

I've installed it and going to take a while to get used to. Allowed Yahoo for example but if I go another area of the site, that little pop at the bottom appears, if I click options it says allow Google Analytics etc...?

So besides identifying scripts (not fully sure what they are but don't sound too good), does the No Script do anything else that's worth knowing about?

Any opinions on it hugely appreciated.