Darin Heinz , Nov 12, 2009; 03:38 a.m.
I recommend using fiber multigrade, archivally processed, for the negatives. The colored filters will work in front of the camera lens and if you are using multigrade paper for the positive, colored filters will work fairly well (because of the light transmitted through the paper going a bit yellow) in the enlarger head. High contrast = high contrast whether neg or pos image is being made. Meter through each filter to determine the additional exposure time needed.
ISO will vary from paper to paper. The way I tested it was to set up a black, white, and 18% gray card on a wall and lighting it with metered light (strobe or sun works well). Make a note from exposure to exposure on the white card itself as to which ISO you are exposing at. Select the one that has the best representation, and use that ISO with that type of paper. Retest for other papers. The paper I use is around ISO 4. Using such a low ISO means you can stop down to f/64 and expose for 4 seconds in daylight without a filter...
I am planning on posting a few negs in the future; I tend to avoid posting many images because of the pesky unauthorized distribution facilitated by the Interwebz.
Hope this helps, Daniel! Good luck!