Jeff Arnold is taking another crack at the online health space after starting WebMD more than a decade ago. Arnold is now teaming with Dr. Mehmet Oz, host of the syndicated "Dr. Oz Show," to launch Sharecare.com, a new health information site featuring expert answers from Oz and other celebrity physicians like Deepak Chopra as well as high-profile institutions including the Cleveland Clinic and Johns Hopkins Medicine.

The new site, launching in the first quarter of 2010, is backed by investors including Discovery Communications, Oprah Winfrey's Harpo Productions, HSW International, and Sony Pictures Television, which syndicates the "Dr Oz Show."

So why is Arnold, who in 2004 told BusinessWeek he had "been there, done that," of his foray into health care, heading back into the field? The entrepreneur, who was most recently CEO of Discovery-owned HowStuffWorks.com, says Sharecare will give the sector a much-needed update online, serving as a "combination of an expert Yahoo Answers with social media built into it."

At the heart of Sharecare will be a social Q&A platform pre-populated with hundreds of thousands of questions and answers powered by the site's expert content contributors as well as viewpoints from consumers who have had direct experience with a condition or illness.

"We're looking to build a collective intellect or combined wisdom so people can have everything they need to understand conditions from credible sources," said Arnold, who has taken on the new title of chief of global strategy at Discovery and chairman and chief architect of Sharecare.

To build up the site's knowledge database, the startup has also partnered with Simon & Schuster to feed all of the publisher's health books into its Q&A engine, starting with its "YOU" series of titles. Users will have the option of buying individual chapters online if they want additional information without having to purchase an entire book.

The site will also gather expert answers from allied properties including Discovery Health, HowStuffWorks.com and Oprah.com as sell as consumer knowledge via the acquisition of Daily Strength, a support group site sometimes referred to as "the Facebook of health."

The site is already incorporating thousands of questions from the "Ask Dr. Oz" section of the companion Web site for his show, which began airing in mid-September. (Before getting his own talk show, Oz had been a regular on "Oprah" for several years.) His limited ability to answer the volume of incoming questions provided the impetus for launching Sharecare.

To help monetize the site, the startup is lining up "Knowledge Partners" -- sponsors that will provide answers in their areas of expertise. As the initial advertiser under the program, Unilever's Dove brand is supplying 3,000 skincare-related answers that will appear along with those from other sources, but be marked as sponsored content. It will also have its own page on the site.

In addition to Dove, Arnold said Sharecare is talking with other brands that already advertise on the "Dr. Oz Show" about becoming sponsors. The site, however, will not include banners or other types of traditional display advertising.

Arnold added that the forthcoming health hub will be promoted via Oz's show and site as well as Oprah.com, HowStuffWorks and the Discovery Channel.