chmod *** file
you need three numbers the first is set for the owner of the file. The second is for others in the owners group and third is for EVERYONE else
the numbers:
1 = execute
2 = write
4 = read
add the number together to set whatever permsions you want. So read and write is "6". Read/write/execute is "7"
chmod 755 file is what you woul;d normally do to an executable or an unwritable directory (like a web directory).
you can also do chmod +% file
where "%" is either the letter "r", "w", or "x" this will add read, write, or executable to everyone.