I find sewing denim extremely difficult. Is there a special type of needle that I should I use?
Denim is generally what sewing machine companies use to demonstrate how tough their machines are. For example, they will advertise that their machines will sew "x" layers of denim. All machines are not made equal, so the more powerful your machine is, the more easily it will handle denim. There is a denim needle on the market, stronger and thicker than regular needles. It will certainly help. As well, avoid thick thread; it makes stitching more difficult. I suggest two things: sew slowly and turn your wheel manually over the toughest spots.