Both of my daughters like to sketch, and so do I. One of our favorite things to do is sit around the dining room table and spend the afternoon drawing. The sketchpad I typically use is the 9 in. x 12 in. Strathmore Series 400. A pad of 100 sheets costs $(removed) on Amazon. I use a variety of pencils and brush pens, but I really like the Black Prismacolor colored pencil (PC935), which is what illustrator Mark Crilley uses to "ink" his pencil drawings. It produces a dark black line that stays put when you erase the pencil marks around it.
Here are a few of our sketches: