Changing file permissions within multiple folders
 

This may be a stupid question but Im trying to change the file permissions and group associations of all the files within a certain directory that contains a lot of subdirectories and files. Is there any way of using a wildcard to do them all at once? I know I can chmod 644 * in each folder but there are so many folders that it would take forever. If anyone knows of an easier way to get this accomplished Id be extremely grateful. thanks a lot

from the chmod man page:

-R, --recursive
Recursively change permissions of directories and their contents.