Fitness magazines can be a great way to stay "in the know" about eating healthy and working out. I have 3 subscriptions to different magazines that keep me in the loop about my favorite bodybuilders, what they are eating to stay in shape and what their workouts consist of.
Although I don't exclusively depend on these magazines to keep me informed about nutrition and training information, they are informative. For example, "Flex" magazine is arguably one of the most hardcore bodybuilding magazines out there and I appreciate it's worldy view on fitness and health. It's not a mainstream magazine, it's more of a raw, no BS perspective on how to get better results from your training. Flex and other magazines that cater to the bodybuilding counter culture are certainly not for everyone.
Women may feel more comfortable with magazines such as "Muscle & Fitness Hers" or "Oxygen." Check out several different publications and find one that you like, consider getting a subscription if you are impressed with a particular one- it will keep you motivated during those boring bouts of cardio.
If you are just starting to get back into a regular workout routine and are looking for some reasonable advice to help you get there, or are a veteran trainer and just needs some inspiring pictures and some motivating training and nutrition articles- check out the magazine rack the next time you hit up the grocery store.