If you are an OHP member, you can borrow a tape recorder for your interviews. Know your recording equipment. It distracts from the interview if you can't remember which direction increases the recording volume, or which little hole the microphone plugs into. You don't want this feature active when you're doing an oral history interview. Use tapes that are 60 or 90 minutes in length, no longer.
Longer tapes are more subject to breaking.
Use wall current, not battery power, when recording. But bring working batteries with you, just in case. Bring an extension cord, too. Bring at least two tapes more than you expect to need. Check the tape recorder and all your tapes before the interview.