It is highly recommended that you link to a specific product with a specific endorsement of such product to generate target traffic if you want to get the most sales. Don't worry, if the person buys something else while they are shopping, you will still get the commission for everything they buy.
Here is the first part of your link that you will use for all referrals:
REMEMBER! You must substitute your Affiliate ID number for XXXXX. We track your commission by this identification number.
Each product below will have a specific code and page you must add to the above link which will send the customer directly to the product you are promoting: it will look something like &u=http://www.chemistry24.com/
Once you sign up, you will be provided with all the resources needed to promote our products. You can call our affiliate manager during normal business hour for affiliate support (1-877-RAPID-10).
If you wanted to send someone to buy the " Chemistry courses", your link would look like this: You would copy code below from the textbox field and replace "XXXX" with your affiliate ID number so that the commision will be credit to you accordingly by your affiliate identification.