If they're unshelled, then you should shell them by hand, which is a bit easier when they're dry; they don't have to be perfectly shelled, either. [substeps] Spanish peanuts are a good choice for peanut butter due to the high oil content.
[header] How to make peanut butter [title] Prepare the peanuts. [step] Before you use your peanuts to make peanut butter, you should rinse them under cool water to get rid of any excess dirt. You can then pat them dry.