Vaguely OT, but does anyone have good information regarding how to identify or block scam/shady websites?

My grandfather tends to fall victim to these types of things - not even always explicit scams like this, but believing hugely inaccurate political websites ( think Obama impeachment conspiracy type BS ), and buying into wonder-products or just the general drivel you see in spammy ads on AOL.

I'm probably going to start by cleaning up his computer some and installing Ad-Block, but most of the links to the websites are coming from his emails - any advice from someone that have dealt with similar scenarios?