Where will traffic to the site come from?

Do you have a target market identified? Beyond "people who need personal coaching services"? (Which is pretty non-specific to me)

Do you know if they are willing to pay for your content?

Just putting up a blog is not enough, for either case.

I'd recommend having your blog & newsletter content be free. These will be key in attracting traffic and gaining your audience's trust before trying to sell them on anything.

Then, you can create some "premium" pieces of content available for purchase - perhaps an ebook or some sort of written guide, membership to an exclusive community of fitness coaches, etc. I imagine you'll be charging for your coaching services as well, so you'll want to have a clear concept of a marketing funnel in place, along with a strong free to paid nurturing strategy.

Happy to hop on a call if you'd like to discuss ideas & strategy further.

With any new on-line venture it is critical to build the user base before charging people for the service. The site has to be the go to place for this type of information and discussion to show the foundation value and then adding services that provide additional custom value add. Simple example is Wattpad with over 30M users sharing free stories, in over 50 languages, from any phone, tablet, or computer raised $46M in venture financing in previous round.

I would separate efforts between new and returning visitors. Sites in general that get a high number of visitors on a monthly basis usually have a core group of returning visitors that leverage it for content sharing or expertise on a regular basis.

I suggest starting with LinkedIN or a related community-focused portal first, join discussion groups in your expertise/product/solution area and build your brand as the go-to-person or company for that subject. The next step is to begin cross-pollinating by tweeting your blog posts or group answers with the hashtags that matter to your community.

Blogging, linking to articles relevant to the user base, also curating news from social media feeds through sites like Paper.li or Rebelmouse provide an easy content option without much effort.

For new visitors, media exposure and references from top opinion leaders in the space can help. I would look to other portals in the same industry or that attract the same age group being targeting and request the site owners to write a piece, send out a communique and/or reference your service to the targeted audience. Getting local media in your areas to report on your service can also provide exposure. I would focus on finding the free avenues first and when you find the highest referring sites, focus any ad dollars there to get the best bang for the buck.

At the beginning, do some research on similar offerings from your peers or competition in personal coaching services to see what has worked.

Assumptions:
- You know and have intelligence about your target visitors and buyers personas
- At launch there will be low traffic volume
- Blog content will be your method of attracting visitors to your website
- Blog content will be targeted around low-mid competitive keywords
- Content offers will be provided in exchange for emails
- Visitor nurturing will be automated through your newsletter system
- Personal coaching services are system based rather than problem/solution based.

Based on the question and my assumptions, I would recommend offering your content for free. Give offers (more valuable content) in exchange for email addresses and provide more useful content, sell information products/coaching services via lead nurturing automated emails.

Do in-depth research of your offerings relating to the market demand including scenario of current players, if any. Hire a good research company to do the job like www.marketquotient.com .Try to give your competitive edge, may be initially giving everything for FREE.