I am in the middle of potty training right now, so I am just going to give you a few tips. I am not doing a scheduled step by step sort of thing at all, so you would probably want to disregard my approach. I call it the Slacker Mom's Guide to Potty Training. :)
My tips from my experience and other mom's advice are:
Don't force him to sit on the potty forever- it can make them rebel because really, who wants to sit on there for half an hour til something just happens by accident? Kids get bored and fight it if you do that. 5 minutes and an honest "try" should be sufficient.
I've heard that starting them out sitting down makes it easier to get them to poop in the potty, where as standing up to pee means you have to teach them 2 separate things. We're still working on poop, so I can't vouch for that, but that is what I've heard.
Someone already mentioned not lifting the seat for a while.
Let him go naked. My son loves to be naked all day and this is how he learned control. I don't even have to set a timer or anything, he has figured out how to stop it if he starts to pee and holds it and tells me, because the few accidents he had (don't freak out about them) we talked about and just cleaned them up, and he didn't want to have accidents. (Just like Tania described)
Get a seat with the little shield or bump and that helps them not pee all over. I know you already have a seat but I love the one from Baby Bjorn. It adjusts onto the seat and is very stable, and has just enough of a hump that it deflects the pee. It comes off easily but tightens down so that it doesn't wiggle. I got it at drugstore.com on sale with free shipping for about $25. The cheaper ones I have seen/tried are very wobbly. My son figured out very quickly how to learn forward enough that the pee didn't go over the bump. He doesn't even have to hold it, just lean down a little.
I personally wasnt into a separate potty chair that required cleaning after every potty break. I do know people that swear by them and leave them in the room where you spend most of your time, but I didn't want a potty chair in my living room.
Let him watch everyone go potty in your house so he can see how it's done. Especially dad. Have dad talk up his big boy undies and how cool they are. And when it's time to buy big boy undies buy the same kind dad has.
Don't push or stress about nighttime potty training until he can stay dry overnight most of the time. They say you shouldn't go back and forth between diapers and pullups and undies to confuse the kid, but I think if you do one thing consistently in the day and diapers consistently at night it should be fine. Or if you choose to do pullups they will work at night (not sure how absorbent they are though.) I am not planning on doing pullups, I plan to go straight to underwear once he has some success with pooping on the potty.
I am being very relaxed about it. I figure since mine was so young when he first started peeing on the potty, I have plenty of time to do it without making it a big deal. If he is 3 going on 4 and still not done, then I will try more agressive tactics. My issue currently is how to get him to tell me he needs to poop, and not to just go in a diaper. Like I said, slacker mom approach. But the tips above can work regardless of how you want to go about it.