Yeah, those three HUD stats are good to look at for a beginner.
Voluntarily Put $ Into Pot / Pre-Flop Raise / Aggression Factor
The VP$IP: This is how often they willingly put $ into a pot. If someone is VP$IP 50% of the time you know he's playing nearly any two cards. And if someone is VP$IP 5% you know he's only playing premium hands so you can play against him accordingly (pocket pairs are good, as flopping a set against his overpair is a goldmine). So basically this stat helps define hands.
PFR: This is important because, for example, some people will limp into a lot of pots and have a high VP$IP, but they'll only raise when they have a monster. So if a 35/2/4 player best from UTG, you know he has something big and probably don't want to mess with him.
Aggression factor: This is a combination of things. But what it boils down to is, the bigger the number, the more they raise/re-raise. And of course, if someone raises a lot, chances are he's making a lot of those raises with less than optimal hands.
Someone correct me if I'm wrong.