Yes, You can. Go to facebook.com/ads click 'Create an Ad' in the top right corner. Then in the 'destination address' box at the top of the create an ad screen, enter your Blog URL. That will drive the traffic to your WP blog.

I've found that driving traffic to non-FB pages on FB ads is significantly more expensive than traffic to FB pages. So FB may not be the most cost effective solution.

Yes, you can.

But why do you want to pay to direct traffic to a wordpress.com blog? Wordpress.com don't allow commercial sites and if you are trying to make money from your wordpress.com site it will get deleted.

[DELETED]

I did this a few weeks ago. It was my first time using Facebook advertising and I was pretty satisfied with it. I don't have nearly enough experience with it to tell you this is the better way of Facebook advertising, but here is how it went for me..

I created a Facebook page for my website and made the ad go to the page. There is also a cool option on Facebook ads where you can choose to target those "most likely to like your page".

That was really cool. I got 250+ likes in about 2 hours spending only $50. I was worried that sending people to my page with only 1 like on it (from me lol) would make people leave or not hit the like button, but likes were flowing in as soon as the ad started.

The cool thing is that rather than just send them to my blog and lose them after that, I now have access to their Facebook Newsfeed.

If you make them come to your Facebook page, make sure you have a clear visible link in your info/about box and maybe a few more in your posts.

I would not invest into something that might be gone any second.
As said above, first invest in a site, there are multiple free guides here to learn about setting up a site & hosting.

Or you can make a FB page promoting the product, click are a lot cheaper.

If you are using Wordpress.com then you are not allowed to monetize/commercialize your website.

I highly recommend switching your site to your own web host first so that you do not have any advertising/commercial limitations, and only then start using paid ads.

Thanks everybody for the advice. My site is non-profit so there are no problems attached. Thanks for the concern. The first two posts sorted my problem out now I need to know:-
How and where to place the ad on my FB page.
Will FB allow me to link to a particular post?
Any suggestions on where to site that post? Status, About, a Sticky post or perhaps elsewhere? I hope I am being clear. When I do my FB post that links to my website, whereabouts on FB will I put it?
Any help or advice will be greatly appreciated.
Thank again, T.

yes, of course u can