Part 1 -- Goal Setting
Part 2 -- Resistance Training Focus
Part 3 -- Cardiovascular Training Focus
Part 4 -- Selecting Starting Loads
Part 5 -- Selecting Starting Exercises
Part 6 -- Warming Up
Part 7 -- Stretching
Cardiovascular Training Focus
If you're like most people, cardio will fit into your goals somehow. Marketing aside, there is a reason why the average gym has a dozen of each cardio machine, whereas having that many of each item of strength equipment would seem ludicrous. In order to be all-round fit, you're going to have to do some form of cardio (in saying that, you don't necessarily need to be all-round fit, although for most of us the benefits are worth it). Like resistance training, cardio can be broken down into a couple different generic areas:
Aerobic The most common type of cardio performed. Stereotypically, this is a go-to for many and poison to everyone else. If you can do it for more than 5min consecutively, it's probably aerobic.
Anaerobic This denotes high intensity cardio. If you can't keep it up for 5min, it's probably anaerobic. Anaerobic fitness can be further broken down into energy systems that last for minutes down to energy systems that are depleted within seconds.
One key thing I'll point out right now is that cardio is not necessary for fat loss. Ultimately, that comes down to calories in vs calories out, and (to a lesser extent) the maintenance of fat-free mass. Cardio is useful for getting rid of calories, so it contributes to the calories out part of the equation, but so does resistance training, and so does incidental activity. Cardio's a weight loss tool, not a weight loss rule.
As a general prescription, I would recommend that complete beginners focus on aerobic fitness unless they need to improve anaerobic fitness urgently. Much like resistance training, this largely comes down to matters of technique, safety, practice and thinking. It also comes down to the general issue that you need to be able to walk before you can run, and you need to be able to run before you can sprint (there are many other exercises you can do for cardio, but you get the point). Besides that, if you're doing resistance training in accordance with the previous section's recommendations, then you'll be doing frequent bouts of about 1min loaded exercise at a time with your resistance training, which will be developing your anaerobic systems anyway.
You'll notice I mentioned technique in there. In general, people are more or less willing to accept that they need help learning how to lift weights safely, but aren't so easily convinced when you tell them they don't know how to walk 10 feet. Technique does still need to be learned with the movements you'll be performing for cardio. Considering you'll be doing thousands of repetitions of those movements, and 1 bad rep is far less harmful than 1,000 bad reps, I hope you'll see the benefits of learning to move decently up front.
A few general methods of cardio are as follows:
Steady State Also known as LISS or MISS (Low/Medium Intensity Steady State), LSD (Long Slow Distance), or getting off your arse and going for a run. Basically, you'll be doing one activity, and you'll be more or less maintaining the same intensity as you go.
Circuit Training This is a decent way to combine aerobic with anaerobic training. Normally I program circuits with resistance training exercises, but you could program them with more conventional cardio exercises. Basically, you'll be taking a group of exercises, and performing them for a short duration each, but back-to-back with minimal (preferably no) rest between exercises. This more or less causes anaerobic conditioning at a local level (in whichever muscles are being used for a specific exercise) and aerobic conditioning systemically, as your heart rate and breathing will be continuously elevated as you work through each exercise.
Interval Training This is where you'll be intentionally varying the intensity throughout the workout. Most interval approaches that I've looked at or used have intervals lasting for as little as a few seconds through to a couple minutes. As a beginner, the preferred intervals will be at medium and low intensities, so it might look like 1min of jogging alternating with 1min of walking. This style is often used with a progression on the duration of the medium intensity intervals, to help you build up to MISS. As you get more advanced and are ready for it (in terms of cardiovascular function, proficiency of movement, having a good approach to pre/post-workout nutrition, having good joint health, etc), you might move up to HIIT (High Intensity Interval Training), which will typically mean alternating between intervals at a high intensity and at a low intensity. If regular intervals can be broadly categorised as jog/walk intensities, HIIT falls more into the realms of sprint/walk intensities. HIIT is very anaerobic.