Using grml-terminalserver you can boot grml via network. If your computer is able to boot via PXE (Preboot Execution Environment) all you have to do is start grml-terminalserver on the host which should serve as booting server and boot Grml via network/PXE on the client(s) then. If your computer can't handle PXE you can still try to boot Grml via network, because grml-terminalserver lets you create a floppydisk including a bootimage with your networkcard-driver to boot via network. If that's still not an option for you check out the iPXE project.
How to start grml-terminalserver? Just invoke grml-terminalserver as user root and follow the instructions. Take a look at the manpages grml-terminalserver and grml-terminalserver-config.
Boot Grml without grml-terminalserver?
Sure - of course you can boot Grml via PXE without having to use grml-terminalserver (for example if you already have a working NFS, tftp,... infrastructure). Take a look at the instructions in the grml-wiki.
Select ip address range for clients
Are there any computers without PXE?
Select networkcard drivers for non-PXE capable computers
Write grub image to floppy disk?
Known Issues / Further information