How do i monetize my knowledge in a niche.

Hi guys,

I come from a Health and Fitness background offline, im no longer working in it now, i worked in telesales until recently before being laid off, however i have a vast amount of knowledge in Health and Fitness and a lot of time at present to do something.

I was wondering how to monetize this, do i make a niche site or what ?

I keep reading about Wordpress, is it free to set-up a blog, do i need hosting, domain etc for this?

I have been saving my paypal earnings to try and cover 3 months of hosting, domain registration and Autoresponder costs, hoping that maybe after this time i can make some money to continue paying these costs online without investing with offline money.

I make a little bit of money here and there mostly from squidoo, surveys, Paid to's etc, but it does not total up to much each month and can be quite inconsistant.

I am currently also trying to save for Market Samurai as i have used the trial version recently with all features and loved it, however its very expensive for someone with no budget at $160 odd.

Surely with all this knowledge im sitting on a gold mine if i can monetize it, any suggestions or guidance would be great.