Using the DeWalt DCF414B is easy. First, make sure you have the right nose piece for the size of the rivet you're using. You can change the nose piece without any tools, and there's a place on the tool to store it. Then, insert the rivet into the nose piece. Next, connect the battery (which you need to buy separately). Once the battery is in, place the rivet tool over the rivet and squeeze the trigger. The tool will pull the rivet until it's properly fastened. As for the number of rivets you can do per charge, you can expect to fasten up to 300 rivets. When it comes to maintenance, keep the tool clean. After each use, wipe it down to remove any dirt or debris. Check the nose pieces and replacement jaw set regularly for wear and tear. If they're damaged, replace them to keep the tool working well. Also, store the tool in a dry place to prevent rust. And always follow safety guidelines when using any power tool.