Affiliate Marketing Secrets

I’ve recently registered a sweet domain name that I’m going to use to launch a site that gives readers free coupons, samples, etc.
The last thing I want to do with this site though is be forced to fill it full of affiliate marketing and things like ‘Get a FREE Apple iPhone’
I’ve taken a look at a number of similar sites and my question to the community is: where do these sites find their content? They seem to have legit deals, offers, giveaways, coupons etc from reputable businesses. Is there a directory where companies go to list all of these deals and offers?
As I mentioned, I’m not interested in turning this new site into a SPAM-ATHON so if anyone out there knows if there is a place(s) where a publisher can find these types of offers and then post them to their site, i’d be forever grateful.
(Note: I know there are a number of these sites around already but I’m having a crack anyway :P)
I’m really looking forward to some of your insights 🙂
Thanks!