I wouldn't worry about it unles it's staining?
Generally blood is not infectious - as it is inside your body! only if you were REALLY sick at the time would it even have a chance of being.
It is actually the other way round - the external world can infect your blood - make sure to treat the wounds properly - use a anti-bactrial wipe and a band-aid.
For your powerbook, turn it off, unplug it, take out the battery and use a slightly damp cloth with some washing-up liquid and just give it a wipe!
Don't worry, as long as no-one licks dripping pools of blood from your palm rests will anyone get infected!
Hope you get better, and be more careful!
P.S. - I'm really sorry if you meant you had HIV or AIDS or another infection carried in the blood. If so the above procedure should work, but you may wanna use a tiny bit of anti-bacterial cleaner too.