what you need is a spirit level and a hard backed book or a bit of MDF (anything hard and flat that will cover the whole saddle from front to back) and a tape measure ... if the saddle has a slight lip to the rear it still works.
Now place the bike so it's a upright as possible (against a wall or someone holding it) loosen the saddle bolts (just enough so you can move the saddle with little force and not as loose as to flop down) place the book or whatever on the saddle and the spirit level on that. now tilt the saddle until the bubble is perfectly level (that's your starting point).
Now tilt the saddle forwards until the edge of the bubble touches the line to the rear of it (if the saddle has a rear lip then 1/4 of the bubble over the line) and begin to tighten the bolts, while checking the bubble remains in the same position (on two bolt clamping systems, do the rear then front and so on a little at a time)
Once complete, measure the distance from the frames cross tube to the nose of the saddle and write it down. Now go for a test ride, if the saddle seems too far raised at the front, then it's a simple matter of placing the tape measure in the same position, loosening the bolts and dropping the measurement by about 10mm at a time.
Once you're completely happy with the position of the saddle, measure from the top tube to the saddle nose again and keep that measurement safe, it'll make it easier to set up next time.
I know it seems a long drawn out process, but measuring for a bike fitting is the same.
