The basic principles of recording interviews have not changed dramatically despite radical shifts in technology. A good microphone poorly placed, or a fine recorder set incorrectly, will yield a poor result, while budget equipment thoughtfully used can provide excellent results.
There are a few general tips that can be applied to any recording rig, keeping in mind Oral History Audio Rule #1: Sound is the heart of the oral history interview, even in video oral histories. Audio quality matters.
Most oral historians are to one degree or another gearheads. Story-loving, yes, archivists at heart, that too. But eventually they must intersect with recording gear, and have some sense of what equipment they prefer to use, before they can revel in recorded sound as recorded history. Getting to know the gear is cheaper than it used to be, but the surfeit of options keeps the process satisfyingly complicated for those who want to take deep dives. Rather than provide a list of links to gear we like, which will certainly be obsolete within months, we have some generalities to offer up for those looking to build a rig, and trust you'll be able to Google around to find the products mentioned.