Chmod

hi guys. im aware of what CHMOD is and how to change it. i just have a few questions
1 - i want to put my php includes in the same folder as my php scripts. do they need different permissions?
2 - i assume that the owner is the server, the group is the other users on the server who are asigned as the same group (or just the other people on a shared server?) and the user is the user. is this correct?
3 - assuming that my php scripts are formail scripts, what permissions would i be wanting on these files and the includes or shall i just chmod the folder?

this questions makes sense to me, but then i already know what i mean. if its not clear please say so and i will try to make it more detailed

thanks