1) First you need a singer.
2) Singer needs a microphone (and probably headphones).
3) Microphone gets plugged into microphone preamp. If it is a condenser mic, make sure phantom power is turned on, or it won't work.
4) Take the output of the preamp and connect it to one of the line inputs on your Pro Tools interface. If you are using a Pro Tools interface that has a built in mic preamp, like the 002, then you can just use that instead of step three and four.
5) Open up a new session in Pro Tools. Create a mono track.
6) Assign the input to the same channel that is connected to the mic (or mic preamp).
7) Press record on the transport window. (Or use one of the various keyboard shortcuts to start recording).
8) Tell singer to start singing. Adjust preamp level so meters show a reasonable level - not too loud or too soft.
I think that about covers it. Didn't take anywhere near 45 minutes, so no charge this time.