boot the system you need the file to be in, and navigate to the other systems folders.
Yes.
Yes.
Get Linux!
So that you can choose to load either linux or (usually) windows.
Dual-boot or multiboot.
Yes you can. Ubuntu's WUBI uses the Windows bootloader (NTLDR) to boot Linux. It also uses the Windows filesystem (NTFS). This, however, is not the traditional way to do things. The traditional way to dual-boot Linux and Windows is to use a generic bootloader such as Grub to boot both Windows and Linux.
"Mode?" They're two separate operating systems. If you're in a dual-boot, you simply reboot and select Windows instead of Linux from the boot menu.
You can. But the Windows installation does not put an entry into it's boot menu, so you have to manually copy a boot sector, and modify the boot menu so you can boot Linux. Linux distributions expect that you may want to dual-boot, so they detect Windows and set up an option for it automatically. For convenience's sake, it is far easier to install Windows first.
Yes. Doing so isn't particularly difficult, and most Linux installation discs can guide you through the process.
install windows first and then install linux, there should be a partitioner in the live cd. or just use wubi
In Linux, we have a menu.lst file in boot/grub folder in which we can change the boot order and timeouts.No idea about Windows.!.
Boot Camp is designed to help people setting up Windows operating system under back as dual boot solutions. Running Linux under Mac is a bit more complicated, there are other solutions of Mac/Linux (dual boot) Mac/Windows/Linux (triple boot). Installing Linux on a Mac with other operating systems on board requires advanced knowledge (especially boot loader [rEFIt] and Linux kernel compiling).