Ad networks, SEO, so on...

What are the first steps I should take to start getting advertising on my site?  Do I have to pay to join an ad network?  What are the best ad networks for dating sites?  Do I have to establish a userbase before joining an ad network, or can I sign up for any before opening my site to the public?

Where should I begin?

Furthering this, what are the best free ways to start advertising or submitting my site to search engines/lists?

Adsense is one that often comes into mind but remember that Adsense has to be on a site with original content (of course Google allows the big boys to break the rules but we are not the big boys).  In other words, Adsense can not be on a site where people post YouTube videos and photos that are not their original content.

I've found some alternatives to Adsense, I really don't think I'd be approved (or stay approved).  I plan on it being a legit business, with nothing pornographic or offensive, but Adsense guidelines just look a little crazy for me to commit to at the moment.  And I think they expect you to already have a certain amount of traffic before even considering a submission.

I'm just not clear on how they work.  Do you have to pay them to get in?  I keep seeing "Daily Budget" types questions on them.  I understand the " you have to spend money to make money" dilemma, but I'd like to make a little and see something coming in before I'm doling out cash for "premium" services.

Any ad network suggestions (besides Adsense)?

(I apologize for my sometimes long-windedness)

 Most of these are relevant but old post.

https://www.google.com/#q=alternatives+to+Adsense+site:boonex.com

 Adsense is a free account to make money for you, Adwords are where you create ads with Google to display elsewhere.

Following a few simple guidelines which are common sense; if you don't own the content or it is on chat pages where content cannot be "moderated" you run into problems.

Thanks newton, I'll research Adsense further and check out the link you gave me.