[This answer][1] from [librik][2] covers advanced functionality and behavior of `Read` et al. that is often unknown or misunderstood, based on other questions and answers I've seen on the site. (I know I learned from it.) As such I think it deserves additional attention.


 [1]: http://mathematica.stackexchange.com/a/17875/121
 [2]: http://mathematica.stackexchange.com/users/1638/librik