if you buy a cheap tap and die set you may find yourself starting a thread titled "shit, how do i remove a broken tap from my cyl head".
sometimes cheap tools are ok, sometimes not. taps are one time that they are not. i've had the cheap sets and most of them are broken. at the very least get a craftsman or vermont. you dont have to buy the whole set if you dont want to part with that kind of cash. just buy the tap you need.
if you want to practice first, buy a couple of extra nuts and put them in a vice to practice on. its really not that hard.
also a square socket or a tap socket will help you keep the tap running straight. they work better than the little tap wrench you get in a set.
good luck.