This kit from Sportsman's Guide has been mentioned on this board before, but I thought somebody might profit from me mentioning it again. I just bought two for Christmas presents for my adult kids (one is a contruction worker, the other has a wife and toddler), and I got one for my own work truck as well.
Some comments here at DC were from guys with medical training who said the kit was very good and surprisingly low-priced ($20). So if you needed an idea for Christmas, here it is. (Of course, there are many others on the market, or you could make your own.)
Now I'm on the lookout for the right book to go with it so I can learn what all those doodads are good for.