Compared to a lot of sports, running is very simple. You just put your shoes on and off you go. If you're venturing on trails, though, it's good to think more about your kit. Decent kit will make the run more comfortable, enjoyable and safe.
The most important piece of equipment for any runner is a comfy, well-fitted pair of running shoes. Go to a specialist independent retailer for good, impartial advice on what best suits your intended use. Balance grip and cushioning against where you're going to run. Big lugs are great for mud, but will wear down quickly on hardpack terrain and can be slippery on wet rock. A low-profile shoe will give more ground feel and can be less slippery, but doesn't offer as much cushioning. For a lot of Sheffield’s open spaces, a hybrid urban-trail shoe is a good bet.
For many women, it's amazing the difference a sports bra can make to the comfort of a run.
Cotton socks hold moisture and can increase the chance of getting blisters. Running socks, however, are designed to wick moisture away from the foot and fit snugly, meaning they're more comfortable to run in. If your toes are rubbing, try socks with individual toes.
Running clothing is designed to be light and made from wicking fabric that takes sweat away from your skin. Good quality kit will keep you comfortable when running, and lasts wash after wash. Often the cheaper kit has a chemical sprayed onto it to give it wicking properties, which sounds great: until it washes out!
Breathability is the top consideration here. There's no point keeping the rain out only to be soaked to the skin by sweat. Good running shops will know the breathability rates of their jackets and be able to advise you on what will be best for where you are running. Those heading out into the hills in mid-winter will have different requirements to those planning a couple of hours on the edge of the Peak District. Jackets are designed to protect you from the elements and potentially save you from the worst the weather can throw at you.
The beauty of this sport is that as your running develops, so does your kit list. Buy good quality and it will last years, seeing you through every season. Most of all: have fun and be safe out there, with kit appropriate to the time of year and the conditions.