The glidepath for the PAR is usually 3 degrees unless otherwise noted. So, set the VSI appropriately and make corrections based upon the calls. If you have never done a PAR before, I really recommend doing a practice approach at your closest available field (rapidly becoming only Navy and Marine fields). They are usually kind of fun for guys that have never done them before. If you have a HUD, it takes all the work out of it. Set 3 degrees with the velocity vector and take a break.
For an ASR, you can either be given step down fixes or just told to descend to the MDA. Usually similar stepdowns to the Tacan approach. If they are using PAR to give you the azimuth for the ASR, they will often give you recommended altitudes every mile or so based upon a 3 degree glidepath. I use the 'dive and drive' method for ASRs though just like a Tacan.