Lens: Mostly fast lenses. What I have is 50mm f/1.8 but during these shots, I used my kit lens 55mm.
Not to mention I shoot in RAW at that time although I wasn't so sure what I was doing.
Basic things a photographer needs to remember and apply when taking portrait shots are the Three-Point Lighting. Now just because I said that means I know what that is. To be honest, I hve no idea but thanks to Mr. Wikipedia, he has all the answers.
The Key Light or the main light. It's usually placed to one side of the subject's face, between 30 and 60 degrees off center and a bit higher than eye level. This is the brightest light in the room btw.
The Fill Light is placed opposite the key light. It fills in the or softens the shadows on the opposite side of the face. The brightness of this light between 1/3 and 1/4 that of the key light.
The purpose of these two lights is to mimic the natural light created by placing in a room near a window. The daylight falling on the subject through the window is the Key Light and the Fill Light is reflected light coming from the walls of the room. Hey that's not a difficult to understand.
There are lots of additional lights on Portrait Photography. The placement is just a matter of taste and technique.
Remember, it's not the end of the world if you can afford only 1 light. Reflector is the answer to that worry. It is placed below the subject's face.