I see countless threads on mumsnet where women talk about wanting to "tone up" and lose weight in which they discuss maybe taking up jogging or taking a class. Or asking which treadmill or elliptical to buy. It really frustrates me and makes me sad because I know that so many people are mostly clueless about fitness and weight loss.
There are many thousands of people grinding away on treadmills, taking "bums and tums" classes, etc. Most of them don't lose much weight. Quite a few lose none.
There are things that do a lot, and there are things that do relatively little, to help you lose body fat. Most of us have other stuff to do in life and so even carving out three hours a week can be a challenge. You need to know which activities are the best use of your time.
In order of efficacy and importance, here are the things that you can do.
- Diet. Nothing is more important. You cannot lose fat unless you eat fewer calories than you burn. You can improve strength and endurance and feel great, but you won't lose fat. Most people need to count calories to eat fewer calories but some have success with cutting out carbs, booze, intermittent fasting, etc. These are just ways of cutting calories.
- Weight training. Lifting weights, whether by machines or barbells kettle bells. This burns calories and triggers your body to preserve muscle mass while letting go of fat. Without this, step one will result in losing both fat and muscle. People who diet + lift lose more fat than those who diet + jog. The weights have to be heavy. If you can buy them at TK Maxx, they're too light.
- Sprinting, aka anaerobic interval training aka tabata. Incredibly intense running or cycling at a level so high that you can just barely do it for 20 seconds (you're miserable at 15 seconds and collapsing at 20). Work for 20 seconds, rest for 10-20 seconds. Repeat about 8 times, a few times a week. This burns calories for up to 36 hours after you quit. It literally raises your metabolism.
- Aerobic Intense Interval Training. Like above only at a level where you can sustain it for two to three minutes. You're gasping for breath and your heart is pounding. Work for 2 minutes, rest for 1-2 minutes and repeat 6-10 times. This also has an "afterburn" effect on the metabolism.
- Higher intensity steady state aerobic training. This is a brisk pace that you can stand for 20 or 30 minutes. You're breathing heavily through your mouth. Feels nice and you you get sweaty but you don't burn many calories. Once you stop and your heart rate returns to normal, you cease burning extra calories.
- Low intensity steady state cardio. This is walking. It has negligible effects on fat loss.
This is all explained in more depth, with links to the science to back it up in this fantastic article:
www.t-nation.com/training/hierarchy-of-fat-loss
I am losing weight rapidly and toning the hell out of my body with 1, 2,and 4. I know that 3 (tabata) is more efficient than my HIIT circuits but I am a wimp. 
These things aren't easy. They require commitment and you may have to learn new things. It's possible, but not easy, to do it at home with the use of books, YouTube videos and weights bought at home. Even joining a gym only gets you so far if you're clueless about the equipment. But I think it's worth it. Once you have overcome your fears and learned how to exercise properly, you'll be set for life.