There is no “one size fits all” plan and whilst following a generic plan can help you get started, it is often a frustrating path. The best investment you can make is to get yourself a trainer. A trainer who will design and individualize a training and nutrition plan specifically for you, your goals and needs. You will start out doing things the RIGHT way, instead of just randomly going in and doing whatever you feel like when you feel like. The benefits of having a trainer also includes accountability (which is very important), having someone there to show you the correct technique for each exercise (also very important – poor form leads to injury, ineffective and inefficient training, and is detrimental overall), and teach you about what you are doing and why, so that you can understand everything, with the eventual goal of being able to know what to do for yourself.
Training
Learn and understand the importance of resistance training, cardio should not be the focus (in all honesty, you do not even have to do cardio to get the figure you want, but as you get more experienced with training or want to improve your cardiovascular fitness, then it can be beneficial to include).
Weights
Anything from two to four days of training per week is ideal to start with, especially in the gym. Each body part should be trained once a week, giving it plenty of time to recover before the next training session for the same body part.
Resistance exercises you should be doing are multi-joint, compound exercises, as they use more than one muscle, and are the most effective for not only building muscle, but also in burning fat. Compound exercises require more body parts to perform than isolation exercises. The best compound exercises that you can do are the squat and the dead-lift as they use pretty much every muscle in your body. Other compound exercises that are good to include are the power clean, bench press, shoulder press, pull-ups, dips, and calf raises (the only isolation exercise that’s really good).
Complete at least two exercises for each muscle group, with four sets of 6-10 (even up to 12) reps per exercise, with 1-2 minutes recovery in between. Always lift as heavy as you can for the number of reps you are set; the weight should challenge you... if it is too easy, you are not doing yourself any favors.
Be sure that you always use good form for EVERY exercise; otherwise you are putting yourself at risk for injury. All reps should be controlled and with good form. It is not about how much you can lift, but how well you lift. You WILL get stronger as you keep at it.
An ideal training time is 40 - 45 minutes; otherwise you become too catabolic and can end up losing muscle, which is not desirable.
So that your body does not get used to your training and stop adapting, every 4 - 12 weeks make small adjustments to your weight sessions. Adjustments do not have to be drastic and simply increasing the weight for the same session from one week to the next is a change that can make a difference. Other adjustments can include changing the order of exercises in a session or the number of sets and/or reps that you do for an exercise (and it only needs to be one exercise changed at a time, small adjustments over the weeks, not a complete overhaul of everything!).
Cardio
If you ARE going to do cardio, make it as efficient and effective as possible. If you do High Intensity Cardio or High Intensity Interval training, you can get the same, if not BETTER results with a brief 12 - 20 minute cardio session instead of spending two or more hours a day doing it! If you feel that you need to do more cardio, then you can add a couple of additional 20 - 30 minute moderate intensity sessions to your training week. Skipping, stair sprinting/running, or rowing, are the next highest calorie burners after sprinting.
Flexibility
Don’t forget about adding in some flexibility exercises, ideally 20 - 30 minutes a day on the days you train, preferably after you have done either cardio or weights, while your muscles are still warm, as this decreases the risk of injury. Stretching makes sure that you can move more freely and easily and helps elongate the muscles, ligaments, and tendons, for overall joint health and fitness.
Consistency
Understand that CONSISTENCY is essential; nothing is achieved without it. If you miss days, don’t stress over it; there is no need to “make up” for them either by doing more on another day - just forget about them and get back on track the next day. Remember the 70/30 Rule: As long as you do everything right 70% of the time, the other 30% allows for when things don’t go as planned because life gets in the way or some other reason.
Efficacy
Never forget that when it comes to exercise more is not always best! You want maximal results for minimal time. You also need to remember that some of this is experimental, and about finding what works best for YOU, since everyone is different and responds differently to different exercise programs.