A car alternator is the first thing that all of us try on the journey to wind power, and it is usually a short stop, because a car alternator wants higher RPMs than you're likely to sustain for any length of time. A low-speed, high voltage motor out of an old tape drive is about the best thing you'll find off the shelf. I had a friend give me a pair of 36vdc motors from a tape drive, but you can also get them on ebay for about $30 last time I checked. The best solution of course, is to wind your own 3-phase alternator like Hugh Piggott suggests. He's something of an icon in wind power, and I'd read his site from top to bottom if you're genuinely interested in extracting usable power and not just having a science project: http://www.scoraigwind.com/
Here is a site that's got a somewhat less efficient, but very buildable setup. http://www.mdpub.com/Wind_Turbine/
VAWT performs better with low wind speeds and changes in direction, HAWT is easier to get high enough off the ground that you don't have to worry about low wind speeds and changes in direction. The most efficient production systems are all HAWT, because the relative ease of lifting them high.
It seems like this issue, EL-wire, and generators (including boxing them) are common enough topics that we should just put some guides together to keep everyone from having to reinvent the wheel. I put together an RV guide a while back and got it sticky-ed. Perhaps its time one of us does the same for wind power and generator power.
The road of life is littered with flat squirrels who couldn't decide.