Here are my suggestions for how affiliates can prepare their sites and business. Begin this process immediately.

Identify at risk relationships. Any merchant online who does not collect the tax for online taxable item purchases can be considered at risk. ( Be sure that they collect the tax on their website, do not assume they collect just because they have a brick and mortar store in your state - verify!)

Have at least two safe merchants for every category or product you promote.

Learn your current nexus laws.

Try to find a couple of other affiliates to work with to help organize. Splitting the workload and having someone who understands will help.

There is a lot of information at ABW so read through all tax related forums, especially the NY Affiliate tax threads. Everythging is here.

You can also see

Affiliate Voice is working hard on these issues, the Tax Conference call on Wed addresses how to prepare and is designed for affiliates in any state.