I'm pretty sure you can apply for a Trademark online at uspto.gov. Many people seem to be able to do it by themselves, but read everything on that site carefully, as doing it wrong could make your trademark invalid.
Copyright is automatic in the US (I'm assuming
PR means Puerto Rico). You can register with the Copyright office if you want to be able to sue for more damages, but it usually not necessary.
Patents are another story. After the Lodsys story (Google it if you've not heard of it), most of us in the iPhone developer community are very against patents. And they are expensive to get and to defend. You would usually only try to get a patent if you have investors giving you a lot of money and legal assistance to make your product.
I'm am not a lawyer, the above is just based on being in this business for a while and hearing a lot of stories.