marg: john, if I would go to far and can't get it in tune, do I just go back the other way? How do you know you need to still go a bit more in one direction before going back the other way? But this is only if I am in tune to start and new to pegs, can't say I'm right on but just close.
Marg, here's the trick to putting the bridge in the right spot. First, tune the melody string up to pitch. Close is OK. Next, with a left-hand finger, touch the string lightly directly over the seventh fret. Play the string and take the finger away quickly. You should get a "chime" sound, called a harmonic. It may take a little practice to get that chime every time. But be sure you are over the fret and not over the fingerboard between the frets. The chime won't work.
Now press the string down normally at the seventh fret and play the string. That note should be the same pitch as the chime. If the fretted note is higher than the chime, slide the bridge back towards the end where the strings are attached. Then check the chime and fretted note again. If the fretted note is lower than the chime, slide the bridge forward towards the fretboard a little and check the two again. You may or may not have to loosen the string(s) to slide the bridge. When the chime and fretted note match, the bridge is in the right place.
If you are fretting the low string when you play, you may have to adjust the bridge so the low string is in tune, too. After you have the melody string set, check the low string with the chime and the string fretted at the seventh fret. If the fretted note is high, slant the bridge some towards the end where the strings are fastened. You don't want to move the end where the melody string is, just where the low string is.
If you look carefully at a steel-string guitar, you'll see the bridge saddle where the strings sit is slanted. If the "crooked" appearence bothers you, have a guitar or string repair person reshape your bridge or make a new intonated bridge for you.
I hope I explained this clearly and that it helps.