i use lavalier mics for interviews. either go with a wireless set up or wired. I prefer wired if your subject isn’t going to be moving around a lot. Many mics are made to be connected to XLR inputs. If your camera doesn’t have that, look into getting a BeachTek XLR adapter.
http://www.bhphotovideo.com/c/product/49318-REG/Sony_ECM44B_ECM_44B_Omni_Directional_Lavalier.html
http://www.bhphotovideo.com/bnh/controller/home?ci=0&sb=ps&pn=1&sq=desc&InitialSearch=yes&O=jsp%2Fproduct.jsp&A=search&Q=*&bhs=t&shs=beachtek&sb=ps&pn=1&sq=desc&InitialSearch=yes&O=jsp%2Fproduct.jsp&A=search&Q=*&bhs=t&Go.x=0&Go.y=0&Go=submit
When you interview someone, you should direct them so that they answer your question with complete statements so that in post you can leave the sound of you asking the question out. If you don’t do that, then you’ll need to mic yourself as well, but then you may need another camera, and more lights.
