DarklordKyo said:
how many cups of coffee can I drink before I become crazier than Freakazoid after discovering 4Chan?
A cup of coffee would have around 150mg caffeine. It varies accoriding to size and how much, well, coffee you put inside but it's a usable average. If you've drank energy drinks, they usually have 100mg caffeine in a can (250ml can ones, like Red Bull and store brands - Moster is 500ml and has about as much caffeine as a cup of coffee in total), so you can use that as a comparison - how does a can of energy drink affect you? Or, if it would help, coke has 10% caffeine content (easiest way to calculate it - 1 litre has 100mg caffeine), have you tried to drink a lot of coke in one go?
Other than that, the other general thing I can say is don't go over 300-400mg caffeine - that's around where you OD on it. Meaning, shaky hands maybe and some sweating, so nothing scary but the issue is that any more doesn't actually give you much of a benefit in alertness and stuff, so it's more or less wasted.
That's all the general advice I can give you - it then depends on body type, weight and other stuff. You could very well feel nothing from your first cup of coffee (or nothing noticeable) or you may develop superpowers. Mostly, I'd suggest starting off with a cup and adjust from there. I myself find 100mg should be enough to wake me up...but that's mostly it, I go with 200mg when I need an actual boost.