Let me give you a bit of advice: Use bit when you're talking about a small amount.
Bit is a small but useful word. Like drill bits, which fit on the end of a drill to change its function, the word bit has several uses. Usually, it means a little piece of something, even time. If you ask me when I'm arriving, I might say, "In a little bit." A bit can also be a short theatrical entertainment, the metal piece a horse bites on, or digital information that's 1/8 the size of a byte.