So how often should I train?
For most people 2-3x/week of high intensity training is plenty. Mix up your weight sizes for each workout. On one day, try weights that are slightly heavier than you'd normally work with, another day try a size lighter than you'd normally work with, and on another day go with the weight you'd normally use. This helps you build new muscle and helps you recover faster.
What if I want to train more than 2-3x/week?
If you are going to train more than 3x/week, be especially mindful about how you train. This means you'll need to vary the intensity of your workouts. 4+ intense training sessions/week is not a good idea for most people. Your workouts should look something like this if you are training 4-5 days/week: Day One: 100% intensity, Day Two: 60% intensity, Day Three: 80% intensity, and Day Four: 50% intensity. You can play around with these percentages, they are merely suggestions. You will need to ultimately listen to your body to decide what works best for you.
How do I properly recover from my workouts?
Make sure to drink plenty of water, get good amounts of SLEEP (more training means your body needs extra sleep), and eat a balanced diet. Eat fresh vegetables, fruits, lean/clean proteins, avoid processed foods, starchy foods, and sugars/alcohol.
What does it mean if my muscles are sore all the time - or not sore at all?
Muscle soreness means you are recovering from a previous training session. Some muscle soreness is to be expected, especially after more intense training sessions. However, sometimes I hear people getting obsessed with the sore factor. If you are not sore after each workout, that doesn't mean you didn't benefit. If you are sore all the time, then its probably time to decrease either the intensity or frequency of your workouts or both. If you are never sore, then its time to take some heavier weights (under the guidance of your trainer) and/or increase your intensity.
How do I get stronger, lose weight and avoid workout plateau?
See above. :-)
Happy Training to you!