When you install from source, the ./configure should have been able to figure out where your init scripts go. After it finishes, you are instructed by the script to run make install.
After that finishes, you are instructed to run make install-init or something like that, and so on and so on. After each run, you are given further instructions, so this time, please read them carefully, and you will see exatly where it installs the init scripts, if you choose to do so. I would, since I would hate to have to install all that by hand.