Are there any US Customs duties to import goods (oil paintings)from
Brazil? . If so, how much?  How are they calculated? These paintings
will be resold here in the US

Hello gugoncalves:

It looks like you are in luck. There are no import duties for "works
of art" coming from Brazil.

I was able to find this information out by going to the:

U.S. Customs Service website
http://www.customs.ustreas.gov/

There I was able to find a link to the 

Harmonized Tariff Schedule of the United States 
http://www.usitc.gov/taffairs.htm

which has a Table of Contents at:

http://dataweb.usitc.gov/SCRIPTS/tariff/toc.html

The following section

SECTION XXI: WORKS OF ART, COLLECTORS' PIECES AND ANTIQUES  
http://dataweb.usitc.gov/SCRIPTS/tariff/0204c97.pdf

under subheading 9701.10.00 (found on page 3), "Paintings, drawings
and pastels" shows that there are no duties for oil paintings as long
as they are "executed entirely by hand".

To make sure that Brazil wasn't somehow "exempt" from this exemption,
I checked out:

General Rules of Interpretation
http://dataweb.usitc.gov/SCRIPTS/tariff/0204gn.pdf

but could find nothing there that contradicted the other table. 

To interpret the duty table on works of art (though, in your case,
"FREE" is pretty self-explanatory), read the "Rates of Duty" section
of the General Rules document listed above. This section starts on
page 3.

So, the conclusion is that there's no duty for your art!

If you need any clarification of this answer, please ask using the
Clarification feature - before you rate this answer.

Thanks.

websearcher-ga

Search Strategy:

us customs 
://www.google.com/search?hl=en&lr=&ie=ISO-8859-1&q=us+customs+

the response was right on! Very detailed and very thorough - Thanks a bunch!

There are no duties on this shipment, but there is a Merchandise
Processing Fee.  This fee is based on 0.21 percent of the value of
commercial cargo. Minimum fee for a formal entry is $25. Maximum fee
is $485. United States goods are exempt.

Not a huge amount, but this together with your freight charges and
insurance will affect your product margins.

What you need for this type of answer is a Landed Cost Calculator. 
Check out http://www.tradeprism.com (you do have to subscribe for the
service, but there is a Product Demo which explains how calculations
are worked out).

Also don't forget to screen your trading partner against the
Restricted Parties lists produced by the US Government.  The new
Homeland Security initative is there to make sure all US companies
know their trading partners.

Good luck.