1. Become an affiliate for ClickBank products

You can easily sign up as an affiliate via http://clickbank.com  and then take a look through the full range of products in their marketplace for products you'd like to promote, for example by looking in the appropriate category you should find products that match up well with your existing business and that you'll be able to promote to your mailing list.

To promote a product, you simply create a hoplink, which is of the following format:

http://hop.clickbank.net/hop.cgi?nickname/merchant 

Just replace 'nickname' with your own ClickBank nickname, and 'merchant' with the nickname of the merchant. If you're not sure what the nickname of the merchant is, you can always go to their sales page and extract it from their sales link - it's likely to be in the following format:

http://www.clickbank.net/sell.cgi?Merchant/1/ProductName 

where 'Merchant' is the merchant's nickname.

Or for an automatic way to generate hoplinks, try the following page:

http://clickbanktoolkit.com/promoteaproduct.html