Here's some quick Guidelines for building a 'branding' campaign w/ AdWords:
Choose general keywords which are too far up the funnel to bid on an ROI basis (make sure you're not competing with yourself).
Measure page views, newsletter/RSS subscriptions, etc as your goal.
Budget optimizer can be quite useful if you're just trying to maximize visitors/visibility.
Always use a rich media ad. It could be image, flash, widget, or video - but use rich media.
I'd recommend starting with enhanced placement campaigns (keyword + placement) first so you can measure the effectiveness of your ads, and choose where on a page they show.
Once you fine tune your message, then you can use keyword content, placement, or enhanced to put your message out there. Continue to refine with placement performance reports.
Don't forget to check out RSS feeds as well in possibly placements for targeting.
On nicely targeted sites where the placements are highly visible, don't be afraid to bid CPM instead of CPC (never bid CPM on text or forum sites).
If you have a facebook, linkedin, twitter, etc page. Or, you do newspaper, radio, etc ads -- coordinate the messages.
If you always use a logo in a TV ad, put it in your image/video ads. If you've been using the same tagline in newspaper ads for 10 years, again, use that tagline throughout your online marketing. (At least in your search branding ads; you might use a different message for PPC ROI bidding based upon conversion metrics).
While 'branding' can be useful (and measurable); sometimes the first step is making sure you're all of your marketing channels are coordinated. This can make just as big of a difference as an AdWords branding campaign.