First and foremost, remember that an infomercial - any infomercial - has one objective: to separate people from their money. Keep that in mind as you listen to the spiel, as that will tend to make you more attuned to what is actually being said - and what they are NOT saying.
Here are a few general things to bear in mind:
1) Mentoring (coaching). Almost none of the infomercial gurus utilize actual investors for their "mentoring". In most cases, the "mentors" are third-party telephone operators who have never purchased any real estate. Some of these third party mentoring houses are under indictment for misleading advertising. Before signing up with any mentor program, find out a) if they do their own "in-house" mentoring, and if the mentors are actual, practicing investors.
2) Watch out for the low cost lead-in product that quietly and unobtrusively leads you into a monthly fee debited from your account every month. Almost all the infomercial gurus do this - you pay a low cost for their program only to discover to late that they tap your account every month. Before ordering, demand to know if there are any ongoing costs or fees.
3) Another important caveat - beware the expensive upsells. Almost all the "gurus" you see on TV provide a very basic program lacking in sufficient detail to be put to use. But it does whet your appetite - basically, it is a sales pitch disguised as a program, created to get you to spend the big bucks for their mentoring or "boot camps" so you can get the rest of the info you thought you were buying in the first place.
In short - THINK! Do not allow yourself to be sucked in by hype. Check things out. Make sure you understand exactly what you will be getting, and what it will really cost you.