There's actually two opportunities here:
- Paid Site Links
- Organic Site Links
Paid Site Links
This one's not too complicated at all. Simply login to AdWords and create an Ad Extension under the campaign you'd like to add site links to. You can add several site links, so if you're SEO-smart, you'll create some awesome link bait on those pages for visitors who might be inclined to link. I created a plugin that does the job well for me (see http://www.seolinkrotator.com/).
Organic Site Links
Unfortunately, the vague answer of 'authority' doesn't cut it for me and probably won't for the novice user reading this thread. Here's how I have controlled organic site links in the past:
- Keep the main navigation on the website short, sweet and explicit
- Match your anchor text to the page title and heading (h1) as close as possible
- Leverage internal linking (or intra-linking) throughout your content, linking to those important pages frequently
- Nofollow the navigational elements you do not want indexed (Login, My Account, etc)
- Include awesome link bait on those pages
- Include buzz bait on those pages (Tweetmeme, Facebook Like, etc)
- Analyze your Internal Links and keywords using Google Webmaster Tools
- Hold your breath, check back in 2-3 weeks
Both paid and organic can play well together if you're using the same pages for both site link campaigns. The drawback is A/B testing flexibility you might normally be used to having in paid search.