Hi, I'm trying to build kernel and in choosing file system option : I want to select ext3 and JBD. Should I give y(yes) or m(module)? I'm new at this OS, so not very much familiar about this. Any help will be greatly appreciated. Thanks.

say yes if you don't want to use an initrd. Saying yes is recommended instead of module. Also try using make menuconfig instead of make config. Menuconfig is a menu based program and its much easier to use.

Saying "yes" will compile it into the kernel....but makes it bigger. Compiling it as a module keeps your kernel size down but can prove to be problematic, for example if the module required to be loaded to read a ext3 filesystem is actually stored on ext3....you wont be able to load it (although you could mount it as ext2 instead I suppose). I would suggest compiling things you really need into the kernel and other stuff as modules. You can load and unload modules on the fly in linux without having to reboot/recompile. Some things only work as modules and others don't. If in doubt....say "yes".