importing from china

re: the subject noted above: I work for a small business looking to further expand our importing dept. and we are curious as to procedures . . . namely, it's all greek to us thus far. We deal in wall decor and import several containers per month via a third party broker who handles our interests both in China and domestically but given this has proven problematic - i.e. duty fees and tariffs that appear arbitrary, in addition to a lack of transparency, etc., we are seeking to better equip ourselves on all levels so that we may either cut out the middle man, so to speak, or commission another broker. As such, we have taken to researching all applicable info re: the matter - i.e. embassy searches, etc. pertaining to customs, laws, duty fees, tariffs, etc. both in the US and China - but are feeling a bit overwhelmed by the lack of info available - not so easy to navigate from scratch, if you will. Hence, any recommendations you could give would be greatly appreciated - i.e. web addresses, personal experience/knowledge, etc.