Resources

Tools to Measure Keyword/Market Demand: 
 
Use these free web-based tools to evaluate the demand for a particular market or keyword.
 
Yahoo Keyword Selector Tool -  inventory.overture.com
Yahoo View Bids Tool - uv.bidtool.overture.com
Google AdWords: Keyword Tool - adwords.google.com
WordTracker - www.wordtracker.com (free trial)

Consider joining one or more of these affiliate networks to find merchants.
Commission Junction - www.cj.com Linkshare - www.linkshare.com Shareasale.com - www.shareasale.com ClickBank - www.clickbank.com Performics - www.performics.com
One Network (Digital River) - onenetwork.digitalriver.com
PartnerWeekly - www.partnerweekly.com LinkConnector - www.linkconnector.com DirectLeads - www.directleads.com ClixGalore - www.clixgalore.com MaxBounty - www.maxbounty.com DarkBlue - www.darkblue.com

Affiliate Forums and Blogs:

See what other affiliates are saying at one of these forums.

ABestWeb - www.abestweb.com
5 Star Affiliate Marketing Forums - affiliate-marketing-forums.5staraffiliateprograms.com
Associate Programs - www.associateprograms.com
Revenews - www.revenews.com
Return on Affiliate - www.returnonaffiliate.com
Affiliate Tip - www.affiliatetip.com

Product and Service Reviews:
Check out real customer reviews and feedback.

Epinions - www.epinions.com
Bizrate - www.bizrate.com