Where can I find the dimensions of general surface mount packages such as, a 0805 or a 7343-28?
Here is helpful link that lists several SMT/SMD packages. Also, most datasheets will give dimensions along with the applicable size codes. https://en.wikipedia.org/wiki/Surface-mount_technology
http://www.radio-electronics.com/info/data/smt/smt_packages.php is another source for SMD package dimensions.