There are many ways but the most basic are:
> go to CB Marketplace
> choose the products with the highest gravity (secondarily: the Popularity)
> despite conventional wisdom: IGNORE the internet business products - those have super high refund rates thanks to freeloaders and scammers
> avoid the high competition products like diet, weight loss, dating
> go for conventional products with lower competition like wood working, etc
> look for High PR / aged domains from godaddy auctions (use a tool like prchecker.net to check page rank) or yourmaindomain.com (yes you may have to pay a pretty penny for these but it will be worth it)
> either start your own website or buy from a supplier here in BHW or go to flippa.com to buy "off the shelf" CB sites (or PM the seller to help you construct a niche specific one which wd cost $100-$300; a customized one costs $500-$1000 which comes with amazon affiliate functions)
> do some keyword research using "google external adword tool"
> send your researched keywords to a content writer to spew out a whole bunch of articles, make sure that you post 1 every few days or once a week to make them look natural - link the keywords to related pages in your site and to other authoritative sites (google likes this!)
> browse through BHW to get some link sellers and use 1 service every few weeks and never the same one for the same site (for maximum naturalness and maximum link diversity which google likes)
> OR go to odesk and hire an SEO for $5-11 per hour (give the guy a budget to work with per month)
> rinse and repeat - NEVER be impatient, the results will show in 2 months earliest probably 4-6 months
Good luck!!!