A few questions, mostly on Small Stakes Holdem

I just purchased small stakes holdem, the book. I've read a few chapters and question some of their ideas.

They stress the fact that you should just about never cold call a preflop raise. It is my understanding that this simply means calling a raise preflop. They even go on to say you should fold hands like AJs and below if it is raised to you (that you should only be calling with AQ, and raising with the other hands you should be playing - AA, KK, AK.

I think about 50% of pre flops are raised (I might be way off, Im just guessing). Im right with them on which hands to play. And, I get these hands very very rarley. I guess im saying, I have a problem with them telling me to fold AJo or s, A10s, when someone has already raised the pot.

Im playing 25NL, 0.25 blinds. and find that many people raise preflop with garbage. I know Im not being clear... But do you think they are being rash? I know Im picking on a small sample of hands (AJ, AJs, A10s, and medium pocket pairs 7-9, KQs+o, KJs+o)

Should I keep reading or is there something in these words I speak.

PS. as I write, the past 6 preflops have been raised,