The most important piece of equipment you need to clean your gutters is a ladder. Unfortunately, that ladder is also the way you are most likely to get hurt completing the task. Thousands of people suffer ladder related injuries such as broken bones, bruises, or cuts every year according to the Consumer Product Safety Commission. They say that hundreds of people even die from injuries sustained on a ladder. You want to make sure that you are safe when using a ladder when cleaning your gutters as well as taking other safety precautions.
Most importantly, you want to make sure that the base of your ladder is on solid, level ground and not on any ice, snow, grease or mud. The rule of thumb for where to place your ladder: for every four feet high that the ladder is going to go up, the base of the ladder should be one foot away from the house. So, for a typical one-story house, the top of your ladder will be about 10 above the ground and the base of the ladder will be about 2.5 feet from the house. This means that you need a ladder that is between 10 and 11 feet long.
Make sure that you always face the ladder when moving up or down and never carry anything in your hand while climbing. You will probably need a garbage bag and gloves to clean your gutters so you should carry these things in your pocket or wear the gloves when climbing up and down. I find it works best to attach the garbage bag to a rope and then tie the rope to my belt loop while I climb. Then when I get to the top I can raise the bag up and down. Experts will tell you that you must always maintain three points of contact when on a ladder. That means that either two feet and one hand or two hands and one foot must be touching the ladder at any given moment. Therefore, once you get the garbage bag up to the top, use the rope to tie it to the ladder so you can hang on with one hand and clean out debris with the other.
There is one other safety concern that I can think of. I recommend that you wear gloves when cleaning out your gutters because you will be exposed to molds from the wet leaves and debris in your gutters. That moist environment is the perfect place to grow mold and bacteria. Most people will be fine if they wear the gloves and may only suffer the occasional sneeze. However, there are people with severe mold allergies that might suffer worse side effects. If you are one of those people then I recommend that you let another family member clean your gutters and downspouts or hire a gutter cleaning service.