Can't Get my Head Around Placing Ads

I'm not getting it about advertising & can't quite get my head around it. How it works etc. I'm ad free now & $200 + comes out of my pocket for the server bill every month & I'm ready to put up some ads. I'm in a fog of how I go about placing ads on my site. What I need to do first etc.

To place ads it is free for me right & no money upfront?

The ad company has to view my site & approve it then what happens next?

After I find one do they give me a code to put somewhere on the template? Is that how it works or do they do it for me?

Is this all I have to do once I contact an ad company? [HowTo] [3.5] Insert Ads in the forum homepage (Professional Guide)

If this is not the right forum to start these questions, then can you please point me to one that is not vbulletin.com or org

 

Hope this helps!

 

In regard to that link you posted.

Yes, that's all you need to do to insert your ad code...

 

Thank You Outdoor. I guess it was the fear of the unknown for.
Now I can go over to the proper section here on AA & try the easiest ads now for now 1 step at a time