Right.
1) Base.
Wash and dry you face. Don't apply heavy moisturiser if you're using foundation. Use a decent mirror (like a shaving mirror) and good light, by the window is best.
Should you be lucky enough to have perfect skin, even colour, no bags, never oily ot shiny, no spots, no redness, skip to no. 2.
When buying foundation, concealor or powder the colour should match your skin tone exactly, check in natural light if you're not sure or you face looking as though you've been tango-ed. Apply using your fingers or a slightly damp makeup sponge and BLEND PROPERLY - be really careful around the edges of your face and by your eyebrows, use random circular strokes.
i) Oily skin. Use a toner for oily skin and possibly summit like Neurogena "pore perfect" with salicylic (sp?) acid. Purchase a decent oil control foundation - you'll prolly need to spend over £7.
ii) Redness - green-toned correctives are in my experience, of bugger all use. Buy a good-quality foundation with excellent coverage - i.e. a greater concentration of pigment. It becomes even more important to choose the right shade - avoid pinky toned ones, yellow-ish ones will balance you out better.
iii) Zits. Do not squeeze, it will cause scarring and make them impossible to cover (use pore perfect strips for blackheads). Normal makeup will make them worse - use Almay "clear complexion" foundation or similar, I think it is genius, it makes a real improvement.
If you need to, use a liquid concealor and blend well - e.g. if you have dark circles under your eyes use 3/4 dots and blend up using a circular motion, also use a little concealor if you have broken capilleries on your eyelids. Finish with a dusting of translucent powder - this sets the makeup you have applied and helps prevent shine. Loose powder and a big soft brush is best.
2) Cheeks. Use a pinky brown shade of powder and a big brush and sweep a little over your cheekbone. Don't use too much, make sure it's even.
3) Eyes. Bourguais (god my spelling is awful clearly I have spent more time doing my face than my schoolwork) does a brilliant range of shimmery eye colours. Nude shades are almost impossible to fuck up and look nice, but if you want summit a bit more eyecatching green is good. Don't try to put loads of eyeshadow on at once, sweep a light layer across the lid and build it if you need more. Make sure both eyes are even. Don't go beyond the crease on the inner corners but you can on the outer corners for a more dramatic look, so long as you blend well (use a clean finger).
If you have naturally coal-black eyelashes, stop there. If not, put on some waterproof black mascara, any brand will do, maybelline is cheap and fine. Start with the upper lashes and use a light zig-zag motion from the base. Make sure you get the outer corners, make sure there are no clogs and your lashes don't stick together. If they do, take the lot off with vaseline and start again.
Leave eyeliner well enough alone unless you get obsessed.
3) Lips. If you have any flaky skin, rub it off gently using a facecloth when you're washing your face. Make sure there's no foundation on them and they are moist, use lip blam of your choice.
Should you fancy lipstick, don't use too much, don't go beyond the edges of your lips and blur the edges using a clean finger. Unless you have a superb tan or are black, pure pillarbox red or barbie pink is very hard to carry off, an orangy or browny pink or red is better.
Haha having said all that it sounds like you don't need makeup anyways lucky you

If you do try it, have fun, look in magazines (the style section of the sunday times can be great) and remember less is definately more.