Thanks much for the above info GN, it worked like a charm to collect all counties with applicable zip codes to determine Sales Tax from the two links you provided. If anyone is interested in a .csv file thereof in the format that MAGENTO (Community) needs, I tried to attach here, but this site didn't accept .csv. Though you should be able to paste the content into a .csv file and upload to Magento. If the link here doesn't work, I would be happy to email it, just send me a PM.
Also, two tips I found out browsing online:
1) The FL State and County Sales Taxes apply to the actual Item as well as the Shipping charges. So if the seller resides in Florida and a customer living in Miami purchases an item that costs 7 USD and shipping of 3 USD is added, then it follows that the State tax of 6% is applied plus the Sales tax for Miami-Dade County (1%) to the total of 10, resulting in a price of 10.70 USD charged to the customer who lives in Miami.
2) when you go through Magento, the tax should be coded as "added" not "compounded".
I hope this helps.
Sorry, but I cannot guarantee all info are correct or up-to-date, this is to the best of my knowledge