I'm a freelancer and I recently helped build a tax quiz/tool to help other freelancers called Visor Vision. Best part? It's totally free. Try it for yourself at visorvision.co.
Details: Visor Vision is a 2-minute quiz that not only teaches you a few things about tax forms (W-4s, W-2s, W-9s, oh my!) and requirements, but it also provides you with a list of questions to ask your accountant. So even if you don’t know where to start when it comes to your W9s, Visor Vision tells you what to ask first.
Bonus: Using this tool supports work from fellow freelancers like yourself!