I don't want to sound like too much of a dick here, but you need to invest in a poker book and read it. Check out Brunson's SS2. It's great so far - well worth the investment.
My general rule of thumb for bluffing: I hardly EVER do it at this level because of the reasons you stated, but, there are situations where a bluff could certainly win the pot. I would ONLY bluff when I'm last to act and there are 3 or less players who've checked to you. And, of course, you sufficiently feel that the flop / turn / whatever missed everyone.
If you want to beat $25NL, don't be the one making the mistakes ... let your opponents screw up. All you have to do is take advantage.
Maybe I'm wrong. Consult w/ Doyle.
__________________
|