Let me spend some time answering your question because it's one of the top queries I get from other bloggers, particularly after listening to one of my BlogSmart! workshops...
First off, the core answer is actually pretty easy: the best way to generate traffic for your blog is to reframe the question. Instead of asking "how to I get more visitors to my site?" you need to be asking the question "how do I become part of the blogosphere discussion?"
Bloggers that don't get this crucial point end up being tiny islands in a very big ocean. Some of them can gain a readership by being phenomenally good or astonishingly prolific, but that's a very tough path to travel and for most ends up being the blogosphere equivalent of the old Web site complaint of "I've built it, but no-one's come to visit."
Instead, you need to get involved! Regardless of your topic, I bet there are already other people blogging about the same issues, thoughts and ideas, even if you don't agree with them. Join their conversation -- on their territory -- and you'll be leaving your island and joining the party.
Here's an easy tip that I tell my clients: two days a week spend an hour writing one thoughtful and cogent article that's relevant to your target readership. Imagine you're going to be having it picked up and published in one of the key trade publications in your marketplace. Good grammar, good spelling, coherent sentences, and a valuable point or insight are all important. It doesn't have to be perfect, but I promise you, the better you write, the more your potential customers, clients, partners and investors will be impressed.
The other three days of the week? Spend the same amount of time and effort each of these other days, but this time find other blogs that are in your market space and add thoughtful comments to their discussions. Sometimes, when appropriate, link back to your own articles, but other times add your own comments just to participate in the ongoing discussion and, yes, gain some visibility in your marketspace.
Over time you'll gain a reputation as a credible expert and people will start checking out your blog to see what you have to say. Then you'll have gained traffic and visibility in your market segment, which is where it's most important anyway.
I spend a fair amount of my time scanning both blog and news headlines (via RSS using NewsGator Online) and then popping onto other weblogs and adding my two cents. It's fun, rewarding, and helps me gain visibility in a way that writing even the best darn blog could never accomplish.
I hope this helps you out!
Update: on my Intuitive Life Business Blog I just posted a terrific story about how lawyer Daniel Perry got interviewed for a Wall Street Journal article after posting a couple of well-crafted comments on my blog! It's well worth reading and reinforces this article perfectly: Comment added to blog leads to inclusion in the Wall Street Journal.
*Please check out more useful tips from Dave Taylor at: http://www.askdavetaylor.com/how_do_i_get_more_traffic_to_my_blog.html