Strong-willed

All right all you mothers out there...I need some advice. ESPECIALLY if you happen to be a mother of a strong-willed child. Because as it turns out, my child is becoming more assertive and strong-willed by the minute.
When Bennett wants something and I tell him "no," sometimes he smiles at me or stares at me with a knowing look, then turns around and does what he wants anyway. He gets a swat when this happens. This was pretty standard for a while, but now it's getting to where he throws mini tantrums (throwing his head back and crying or screaming) when he doesn't get what he wants right away, like going outside. He's gotten to where he whines a lot when he's not instantly gratified, too. I would say this is just a phase and he'll grow out of it, but it's been a few weeks and it persists, so my question to all of you expert, veteran mommies is, "What do I do?" Do I give him swats for whining or fit throwing? Do I ignore it? Do I put him in his bed? Some of all of it? I'd REALLY like to know what you guys have done and what has worked well in your families. I didn't realize that the older your child gets, the more complicated things get discipline wise (naive, I know). This stuff may seem like no big deal, but my fear is that he'll be two or three years old before I know it and become a child who doesn't obey or is disrespectful because I didn't begin implementing basic discipline standards at an early age. As a Kindergarten teacher, I prided myself on my consistency and high standards in classroom management and discipline, but when it comes to my own one year old, I feel uncertain. I've always been a "trust my instincts" kind of gal, but I'm finding my instincts are falling short this time around! Input would be greatly appreciated.
Oh, and if you have any suggestions for good books to read on the subject, I'd love that, too.