Moving to Spain

Just a quick reply.

no you can't come over on the 90 day tourist and apply here.  Most visas need to be applied for in your country of residence.

you can get a 1 year visa with option to renew for non eu citizens called the non lucrative visa or retirement visa.  you do need to show proof of sufficient funds in savings, cash etc...

A working visa is more difficult to obtain as you usually need a company to sponsor you.  Depending on your age, you may be able to obtain one easier if under 30.

as far as starting your own business, that is call autonomo.  You would need to pay into the social security system each month, plus pay taxes on top of that.  It can be expensive, but worth looking in to.

Thanks for your quick reply. So during my visit to Spain i wont be able to apply for NIE.
Is there a minimum limit for funds?

Even if one starts a SL company , Does he need to pay social security & taxes every month?

Yes starting SL is a higher cost to start and you do still need to pay social security and taxes. 
I don't believe you can apply for the visa while in the country.  I guess if you already have plans to be here for a scoping trip, you can set up a meeting with a gestor or someone to discuss options.  If you want your SL or business to be your means for your working visa, then it may be different.

http://www.exteriores.gob.es/Portal/es/ … trada.aspx