Advice on Advertising?

Hi,
I’m considering adding advertising to my site on a small scale. DEEPERDEVOTION.com has been in existence for four years now and we’ve never officially sold space. We aren’t a huge site and I was wondering at what point advertising becomes possible.

For now, I’m thinking just one spot at a time, in the middle column where I currently have the under oath link (that’s not an official advertisement). I also have a devotions application on facebook that currently has between 400 and 500 users and it’s continuing to grow. According to Google Analytics, we have been averaging about 13,000 to 14,000 page views a month for the last couple of months (this is up from 8-10,000 in spring/summer). I anticipate this to continue to grow as I’ve started the weblog again.

What would be the best way to pursue advertisers for the spot in the middle column?
Should I consider integrating other spots into the site? I also have a daily email that goes out to about 4000 people.
What type of fee plan do you think I should use?
If I’m offering limited placement, how long should I allow a single advertiser to hold their spot?

Any other general suggestions?
Anybody interested in advertising?

Thanks!