Go to:
Page 1: Tools required, choosing a suitable size for the drawing. What paper?

Page 2: Dividing the image into a grid; creating larger images from smaller photos.

Page 3:

Page 4:

Not many artists offer a tutorial of their techniques to aid other people who may be interested in creating their own images.
While I don't consider myself to be in the higher echelons, perhaps my experiences can still help you, even though I've only been doing portraits since 2001!

Tools required
Depends on whether you want to use conventional, or coloured pencils, but try the following:

Smooth surface: Contiboard makes a good, cheap surface to draw on! An alternative is to use the firm rubber mats used by architects for drawing boards.
Graphite Pencils: HB, B, 3B, 5B, 7B
Coloured Pencils: Buy a set of 12 - much cheaper than individual ones. There's no need for 'watercolour' pencils unless you want to experiment with 'washing' to achieve different effects. Some colours won't be available in a set of 12, like Flesh Pink or Orange, but light cross-hatching or shading using two colours gets around this problem. Most art shops also sell individual pencils if you need to fill any gaps.
Sharpener: There are two types - one for harder graphites (for sharp points) and the other for softer pencils (a blunter angle). If you only have a single sharpener this will probably be the former, but you can use this for softer leads, but take care! Alternatively, when using pastel pencils it's often better to use a very sharp knife.
Eraser: The latest 'putty' erasers are nice to use and can be moulded to any shape. Plastic erasers are equally suitable and are better for erasing larger portions and grid lines.
Paper: If this is your first attempt, don't rush out and buy a pad of high-quality paper. Good quality writing paper, like Conquerer, is ideal for trying out your skills. Otherwise, just have a go with normal photocopying paper and if you're pleased with the result, invest in something better.

More Advanced?
Once you've reached a more proficient standard, then you can start raiding art shops for supplies like charcoals, watersoluble pencils, textured papers, tinted papers, and so on.