I am developing a user generated content site right now and its almost finished so I have been researching a bit on what I need to do legally. I know its going to take a lot of hard work and time to actually build a community with a site like this so I am not sure if I should spend the money to file an Interim Designation of Agent form or if I should wait until the site actually shows potential to make money.
Should I do it when I launch the site or wait?
When you think the risk that users will provide infringing content is high enough that you need the safe harbor of the Digital Millennium Copyright Act.
Once you register, make sure that your terms of service provide the appropriate contact information and otherwise are in compliance with applicable DMCA provisions.
Disclaimer: This information does not constitute legal advice and does not establish an attorney-client relationship.
My first inclination would be - just launch it & test your concept. Why put more money into something you are unsure about.