Recently, I've had a couple different people ask for my advice on working out. I think they were probably looking for specifics on the type of exercise I do, but I gave them something completely different. Because that's what I do. I drive people crazy.
Keep in mind that most of the advice below is targeted at people who are just starting to work out...
Schedule it. Make it a part of your routine. Find free time every single day and put it on your calendar. Don't let anything interrupt it (within reason) and stick to it. After a few weeks, it won't even occur to you to skip the gym, it will be a part of your routine.
Keep pushing yourself. If you haven't worked out for a long time (or ever) you'll get tired pretty quickly, but once you get into the routine things will start getting easier. If you want to keep making progress, keep cranking up the intensity. If you're lifting weights, do more reps or add more weight. If you're doing cardio, crank up the speed, resistance or time you're on the machine. If you wear yourself out too quickly you can always ease off, but if you don't go hard enough you'll plateau.
Change it up. This is related to keep pushing yourself. If you don't change things up, you'll get into a rut and plateau. Your body will adjust to the activity levels and you won't make any progress. There are plenty of sites on the Internet that provide all kinds of different exercises and training tips - I'll let you go find those. Use them. Try something different and new.
Do it right. If you're lifting weights, learn and then use the correct form. This will prevent injuries and therefore keep you on track and in your routine. If you have to lift less weight to do it right, lift less weight. If you have to hold on to the treadmill to stay on, slow down or decrease the incline. If you're holding on, you're cheating yourself.
Don't let other people intimidate you. Everyone has different goals and different fitness levels. What's right for you is not right for someone else. Don't let the overpumped dudes who are lifting a ton of weight make you feel weak. Everyone has to start somewhere and you have to start at the place that is best for you. Don't be ashamed. Eventually, you'll get to a point where you're lifting heavier weight or running at a faster pace, but it won't happen overnight. Don't let that get you down.
Be respectful. I've already ranted a number of times about this. Wipe off your machines after you use them. Wear shoes and socks. Wash your gym clothes after each workout. Don't hog the machines. The list goes on and on. In general, just be considerate of the other people there that are trying to get a workout and you'll be fine.
Be patient. Seeing results takes time. Your weight loss and muscle gain won't be like the folks on The Biggest Loser who get to focus completely on working out. Your body will change more gradually, but it will change. Over time you'll see the bulges moving from the wrong places to the right places but that only comes from consistent hard work.
Of course, there are a thousand other things that I could mention like changing your eating habits, but that's a completely different topic. However, I have a feeling that once you start working out, you'll want to change your eating habits. I wanted to, and I did.
Hopefully, some of you find this helpful. Though I've probably driven most of you crazy. That's what I do, remember?