So, strings, what kind of strings should you use. There are two kinds. You'll have either nickel wound or stainless steel wound. This doesn't apply to the plane strings because they're stainless steel anyway. The winding, of course, applies to only the wound strings.
Very subjective, it's just a matter of taste really. There's no right or wrong. They're both fine. You could conceivably buy strings just based on the gauge, and go to your guitar store and get guitar strings. But, there may be some slight differences in how some of the ones that are made for pedal steel specifically are wound over here. I'm not sure if that's the case.
There are several brands, George L's, Jagwire, and John Pearse. They all make good sets of pedal steel strings that you can order.
Now, the gauges, of course, there are more strings than a guitar. So, buying a set of guitar strings is not going to do you much good because you don't have enough of them and they won't be the right gauges anyway. To quickly run down the gauges of the strings that you are most likely to use, you're talking about 013, 015, 011, 014, 017, 020, 026, 030, 034, 036.
Those are very widely used gauges for pedal steel guitar. You can have some of them slightly heavier. Some people like an 18 instead of a 17 or a 22 instead of a 20, but it's not a huge difference. Really, you'll be fine with either one. That's what you should be on the lookout for.
Also, the tuning of the thing is going to be F sharp, D sharp, G sharp, E, B, G sharp, F sharp, E, D, and B.
And that's the basic rundown of the strings.