admin answers:

You do not need a USA TAX number. The companies deal with the taxes, because they are the ones getting paid by other people. The most you will have to worry about is filling out an Online W-9 form. But you aren’t a U.S. Citizen so you wont have to worry about that anyway.

And a word of advice about freelance writing, It pays very little starting off.

I do affiliate marketing and it requires me to write on a blog all the time, You should check out my site to get info on it. Writing and bogging are all good ways of marketing. Http://www.jobbasket.tk

Either way, I hope i could be help

e-mail me if you need anymore information. Cotecason45@gmail.com

-Cote