Bristol Board is a super-smooth super-white kind of paper with a very high weight - it's cardstock weight. The main advantages of bristol board is that it's very smooth and very white. The reason I use this is so that my very hard pencil doesn't leave "dents" in the paper surface. If you try drawing a shape on regular paper with a hard pencil, then erase the pencil, and shade over with colour pencils, you'll see a white ghost of your pencilwork, because the paper has a dent that the colour pencil doesn't reach - it's like a rubbing of your pencil sketch. Bristol board is very hard-wearing, so I can erase my pencils and it stays smooth.

Pigment liners are a special kind of "drawing pen" - they're much cheaper then engineering pens (e.g. the Rotring rapidograph), they tend to cost somewhere between $1 and $2, depending on brand and quality. They feel like drawing with a felt-tip, but the tip of the pen is very precise and gives you an equal width line all the way along the stroke. The ink is permanent and very black, so you can wait a minute for it to dry, then erase the pencil sketch from underneath it. (The left image of the paladin above is pencil sketch work, the middle image is the ink pen after erasing the pencil.) - The most well known brand of Pigment liners is "Sakura Pigma Micron" (commonly called "Microns") - but I don't like that brand, so I use Mitsubishi Uni-Pins and Derwent Graphiks.

Coloursoft pencils are a fairly uncommon type of acrylic colouring pencil - they differ from regular colouring pencils because they have a higher wax content in the pencil lead. This makes them very soft to draw with, and they put down a large amount of very vibrant colour very quickly. (This is ideal for cartooning, but not great if you want to do watercolour style sketches.) - The other advantage that coloursofts have is that the formulation of the lead allows you to sharpen it to a very sharp point (see the green pencil in my image.) - This is great for detail work, or if you draw small. (I draw small.) Coloursofts also have quite a large range of colours and shades that you can get out of a single pencil - The metal on that paladin image is just two grey coloursoft pencils, one light, and one dark. The big disadvantage of coloursofts is that they don't blend well, and they don't erase at all - so you've got to know what you're aiming for before you start.