it can be a bit simpler than that,
when you installed linux, you may have made a startup disk already, excellent! if not, you can make one, as already stated.
Now, as to the lilo.conf, if you are not shifting your partitions around, and if you have not changed your lilo.conf since you installed lilo (assuming you installed it using a graphical install, a la red hat, mandrake and all the other biggies) then all you need to do is reinstall windows, use your linux startup floppy to boot into linux, as root, then run:"lilo" (you may need to type in the full path, eg "/sbin/lilo")
which will write a master boot record based on the info in your lilo.conf
Sorry to basically rephrase what foobar already said, but i just wanted to say that this process seemed confusing to me as a newbie when it's actually incredibly easy.