The Open Tuning
There is a somewhat standard "open" tuning. "Open" means that no pedals or levers are engaged and no bar is used. It is as follows:
This tuning diagram shows the steel guitar from the perspective of the player. The 1st string is the one furthest from the player. The 10th string is the one closest to the player.
The following picture shows where the open notes of the PSG are found on the keyboard for reference. Note that the pitch of the 1st string is lower than the 3rd string, and the pitch of the 2nd string is lower than the 4th string. This tuning anomaly has evolved for fast scale picking purposes as well as for more strummable chords on the center strings.
The tuning of the open strings more or less makes up the notes of the E9 chord (An E9 chord is spelled E G# B D# F#). So this tuning is called the E9 tuning.
Note Range of the Steel Guitar
The E9 neck of the steel guitar has a range that starts with an open string B that is 2 B's below middle C. It is played on the 10th string with no pedals or bar and is found here in musical notation:
The highest pitch depends on how far you can move the bar up on the third string. But at fret 25, the pitch is A that is 3 octaves above middle C. It is found here on the musical staff:
This means all notes available on the steel guitar fall within this range:
About the C6 Tuning
Some professional model pedal steel guitars have another neck on them closer to the player. There are many variations on the tuning of this neck. But many players tune it to the more or less standard C6 (CEGA) tuning, which is similar to earlier lap steel tunings. It is primarily used to get that old-fashioned Hawaiian or western swing sound. Here is the "standard" tuning and pedal assignment for the C6 neck:
Most of the information on this site is for the E9 neck, exclusively. The general information is pretty much the same, but given the difference in tuning, the specifics of the songs and exercises contained herein are different. I plan on adding more C6 info soon.