Recommended SEOers Resources

Hmm, well what are you expectations?

As sadistic as I can be, I don't really want to shoot you down
Its hard to tell without looking at the site, have you monetized it at all? 

There's not really enough information to make a fair guess, so I'm going to assume it doesn't have any Ads right now, and you haven't added Ads to a site before (I'm might be incorrect, so sorry if so)

Have you added Adsense Ads anywhere? 
If you add Adsense to your pages, you will get an idea of how much your site will make a day, knowing this sort of information can help you and a prospective buyer come to a reasonable deal.

If you dont have an Adsense account, or haven't added Adsense why not try it now
Here's some information related to adding Google Adsense to your site:
Ad Implementation

The Adsense Blog might also be helpful:
Adsense Blog Videos

Adsense is far from your only monetizing option, but its a popular one a good one start with
[try to remember to not click your own Ads  ]