As you'll see a lot on the Gamasutra blogs, marketing and community outreach can be one of the hardest and scariest aspects of game development - and it doesn't even have anything to do with development! However, I thought I'd share my two cents on the subject while I'm in the middle of it all.
One thing I've found to be extremely helpful in this aspect of game development is starting early. This too is also something you'll commonly hear said on Gamasutra. The reason, its true!
Set up the twitter account, make a blog page, and just get it all ready now, don't wait until your game is complete! By starting during development, you can occassionally share progress updates, regardless of how meaningless. The cool thing is, even those small meaningless updates you can see at least little gains in your support network. And more importantly, those interested early, will likely be the people that act as proponents of your game when it finally comes out!
The blackhole for intellectual thought - my original name for Twitter. After finally overcoming my fear that its gravitational pull would draw me in, I've found Twitter actually isn't that bad! Not only will you meet a few supporters, there are also the self-promoters on there. These self-promotors may sound bad, but its actually great! You'll find sound engineers, indie reviewers, and much more, that are just eagerly looking for work, so they seek you out and follow you.
By starting up a twitter account early, even with minimal activity, you build a small community around your game. Even if they are all just self-promoting followers, its still followers attached to your account so when you actually prepare for release of your first title, you don't look like the new kid on the block anymore!
If you aren't sure what the tweet about, follow some other indie developers to see what they are doing! They appriciate it, and often will follow you back. On top of that, you can make a contact in the industry that will be interested in speaking directly with you to share their experiences and offer suggestions! It almost might be worthwhile to follow the hashtags #indie and #gamedev - these are a great place to find other developers to track, contact, and maybe even contract for complex projects.
Again, minimal activity during development is still better than no activity! By just recording a few updates during game development, you could again build a small audience for your game before it even comes out. Plus, blogging then gives you something to tweet about! Blogs can provide another added bonus in the fact if is a great way to organize your thoughts during development, and offers a great 'how-to' (or 'how-not-to') guide for your next project, so you can quickly look back and see what you did well (and what you might need to remember next improving next time).
If you can't think of blog content, again, check out other indie teams! I've found the indie development community to be very supportive, so feel free to reach out! If you show genuine interest in their projects, the feeling is often reciprocated!
Feel like your entire life is spent in front of the computer? Haha, why'd you get into game development the fool? 100hr work weeks at my computer - I know thats my life now, enjoy!
The reason I mention podcasts are they can feel like an escape from monotony of work at the computer. Just jump on your phone and record a message to yourself a few times. Eventually you may get good enough to piece together podcasts that can be posted as another way to get your name out there. We are all lazy at times - so reading the thoughts of the world can get tedious. Just sitting in your car, or at the computer playing someone else's podcast while developing requires listeners much less devoted time to your project - and if you are new, they may not want to devote much to begin with, so finding an efficient way to have your ideas reach an audience is key!
Put the content on your website for press / people passing through - they are more likely to click a play button than to read 3 pages of text. Plus, there are plenty of podcasts and radio shows out there looking for content - who knows, maybe one of us will be lucky enough to get picked up!
I don't claim to be a PR genius, not even close. But in my experience, and from everything I've read, getting your name out there is almost as important as having a quality product in the first place - so start early! There are a lot of other ways to get your name out there, including YouTube, Digg, Moddb, and much more - but unless you have someone strickly dedicated to PR, you probably won't have time to do it all just yet. I've found focusing on two or three is more efficient for building interest than just sprinkling info everywhere.
I hope this helps some others just starting out! Best of luck guys, can't wait to see the tweets of your development news!