Can someone direct me to information about:

non-lucrative visa

I am a self-employed graphics professional working virtually who would like to live in Barcelona for a year or so and do a lot of traveling from there.  My income is derived from US clients only and I would continue to maintain a US residence and pay income taxes on the money I earn.

Or maybe a visa really isn’t necessary since I intend to travel a lot. Could I just be sure to plan a trip every 3 months (which will not be hard) so I don’t violate the terms of the 3 month travel visa to Spain?  AND do I have to travel outside of the EU to do that .... or could I just go to Paris or Frankfurt or Milan? And how long do I have to stay in order to return to Spain to renew my legal 3 month visitor/tourist status? 

Hopefully someone can shed light on this issue for me.

Thanks,

Marsha