My advice:
Don't build the site all at once, drip feed out your content. If you are using Wordpress get you a theme that doesn't look like a blog. (I have a subscription at templatesold, find one there you like and I will get it for you.). Personally, I believe an authority site is better when built as an HTML site, with a word press blog attached (And SEO with HTML is much easier). Your choice.
Put up about ten content pages at first, as well as a privacy policy, about us, contact us, and a sitemap.
You should often link from your pages to other authority sites, because if you are a player in your field, and a breakthru comes along, you would naturally link to the information from your site. You would be remiss not to bring at least some developments in your niche to your reader's attention. It would be a glaring mistake for an "authority" site not to link to its contemporaries.
The object is to be seen as an authority, so you cannot black hat this. Make sure that every page and post has a clear benefit for your visitor. Most certainly explore which keywords to optimize for, run ads, tweak and test, but write content for the benefit of your audience.
Don't use popovers, unders, or locks. No doorway pages, no automatically playing sound, nothing that might drive a visitor away upon arrival.
In the health care niche, content is sometimes simple to get. After you have about 20 pages and your site looks good, Start contacting local health care professionals (don't forget government agencies who dispense health information. This is a terrific source of content that they want the public to have). Contact their gatekeeper and tell them you would like to feature the DR, or publish an article from the DR on your site, along with a couple of pics. In most cases, the gatekeeper will pass you right along to the doc, because no savvy businessman will pass up free positive PR. Rinse and repeat. Reporters do this all the time.
(If you are smart, before you go, check out his web presence, get a JV partner who does SEO work, and while talking to the doc casually mention that you couldn't find him on Facebook/he didn't have a website/you noticed a bad review for him online, and you have a friend who can help him with that. Another revenue stream!)
Now go get links, slow, diverse and quality. Find the quality directories in your niche and manually submit your site. Find a local college and find the medical group and let students know that they can publish to your site, if they create a link from their .EDU blog. The link juice from those sites is phenomenal.
Don't be tempted to do back hat methods, don't use spun content, don't use scrapebox (in the usual way people do), don't buy links and above all, stay away from fiverr link gigs.
Use social media, use an op-tin and an auto-responder, use a visitors survey, use your imagination.
Go nuts with your internal linking. If you divide the site into sections, like weight loss and cardio, as much as possible have all the pages in each category link to each other and all of them link category page. Pages within one category should not link to any pages out of their category (unless quoting content). Link all pages to the home page with the exact same anchor text. Ditto for privacy, sitemap, about and contact us, but put them in the footer
The first link on each page has the most power and link juice, so the first link in every single page on your site should be to the homepage with the exact same anchor text site wide, and don't use "home" either, use your main keyword.
Put links to other sites from your pages when it makes sense for the content on the page to have them, and it benefits your readers.
Make the header graphic a link to your home page too, use the keyword for the filename, and alt desc.
When link building, don't forget diversity. Get links from forum, directories, related sites, your suppliers, be all over the place.
When links come into a web site naturally the anchor text is really varied. Many links will be by domain name, or the words "click here", or some variation of your keywords. When you build links keep this in mind, and build some links with these more natural phrases. If your are targeting Seattle optometrist, build liks for eye doctor, my eye doc, or whatever. When you are blog commenting, use a good mixture of synonyms for your main keywords along with your real keywords.
After each new page is indexed, publish every post as an article to the quality article dirctories and make sure the name of the author is the same as you are using in the "rel=" tag. Google will see that you are syndicating your own content, no penalties will be forthcoming. If you spin your articles, make damn sure that everyone published makes perfect sense. Fix all spun articles by hand before they go out. You cannot afford to have a bunch of poorly done stuff out there if you care about credibility.
Do all the proper on page SEO, and make sure to use the "rel=" tag for each piece of content published online.
When you get a Doctor, or nutritionist,or dietician, send out a press release about their upcoming article. To Wit: "Local Doctor to be featured on healthcare website"...or so.
Think, quality AND quantity, a new page every 3 or 4 days until you hit 50, then 1 every two weeks as you go to you next authority suite. At around 50, you can really start to let it go on auto pilot, except for traffic generation.
Avoid flash and javascript based sites.
Pay extra close attention to your traffic patterns, time on site, and bounce rate. strive constantly to improve these. ( Hint: a really interesting 1 minute video above the fold will do wonders for your bounce rate.)
Remember that this is your site, but you are building it for your visitors. The more the site reflects what you want it to reflect the less money you will make. The more it gives your readers what they want, the more money you will make.
In other words, feed your ego, or your pocketbook.
When you get that done, let me know and I will see if I can help you out a little.
(Damn, 1000 words, should have made this a WSO!)
