Where can i get Answers about a 1796 trade dollar?

Answer 1

You mean United States?
Any coin reference book contains information about approximate values. The "Guide Book of United States Coins" by R. S. Yeoman (the Red Book) is the most commonly used reference and is available at any good public library or coin shop.
In addition, there are usually one or two for sale on eBay at any given time. Here is a listing of all 1796 dollar coins presently for sale on eBay - Note that most of them are copies or replicas:

http://coins.search.ebay.com/1796_Dollars_W0QQcatrefZC6QQcoactionZcompareQQcoentrypageZsearchQQcopagenumZ1QQfgtpZQQfromZR2QQfsooZ2QQfsopZ2QQftrtZ1QQftrvZ1QQlopgZQQsabfmtsZ1QQsacatZ11975QQsaprchiZQQsaprcloZQQsbrftogZ1QQsofocusZunknown

I suppose that since you didn't give any details about your coin, it's possible that you have a Spanish colonial 8 reales (which circulated in the US as silver dollars until 1858). If so, you need to let us know what the words on the coin are, both sides, every letter. Those were struck at several different mints (Mexico City, Lima, Potosi to name a few).