is this good soil for prep to lay sod

Peat moss is not soil, per se, but an additive to improve your soil structure and increase the organic content of the existing soil. So, I would not recommend that you just put this down and then lay the sod - it is best used to mix it into the soil that's already there. If your current soil is fairly compacted or has a high clay content, the roots are going to have to really work to establish themselves. If that is the case, I would add the peat moss and either double-dig / garden fork it into the soil, or use a roto-tiller to mix it in. Mechanical tilling is by far easier, and you get a more uniform mixing, but it really disturbs the soil structure and at best, will only get you six inches or so into the soil. It also creates tiller-pan, which could affect drainage and cause unintended issues elsewhere on your lawn (i.e. water pooling in areas, soft ground, etc). Manual mixing (either by double-digging or using a broad-fork / garden fork to turn the peat into the soil) is a LOT more physically demanding, but it better preserves the structure and does less harm to the worms, etc that keep your soil (and by association, your grass) healthy.

It's commonly used to start seeds or used in gardening because it retains water well if kept moist. If you're going to be mixing it with other amendments I would say yes it would be a good prep to lay sod, but on it's own, no, not to mention expensive.