promote website on twitter?

Hey, I'm just starting to learn about using twitter for marketing. Basically, I want to drive targeted traffic to my site (obviously). Just doing a twitter search on my niche, I see people tweeting about stuff & I know they would like my web site. My site is informational, its not a landing page affiliate thing.

So my question is how should I go about this? I've been reading up on twitter and see that you can only direct message someone who is following you. But if I tweet an "at" type tweet then everyone following me will see the tweet. Obviously that will piss people off who are legit following me if I send out 50 tweets every day with my link.

So I was wondering if you black hat guys have a method you use. Can I just set up a dummy account, use twiends to get like 50 followers so it doesn't look like a completely bogus account. And then just start tweeting people, not really caring if I piss off the twiends followers?

Is this what everyones doing? Is there anything I need to look out for, like a maximum number of spammish "at" tweets with my url per day? Is this even technically against any rules? If someone tweets "i suck at math" & I then tweet them a website about math, is that eve considered spam?

sorry if this is all common sense to you seasoned black hatters

i see now thats probably considered spamming.

so do i have to use proxies and all that stuff? i'll pay for info btw