Weekly Running Distance during Training For Half Marathon And Marathon

I have lots of weight. At the moment I run 5 km every two or three days, plus I train in the gym. I limit my food consumption but sometimes I can break my diet and begin to eat a lot.     

I would like to take part in a marathon.        

How many times a week do I need to run (how many times a week and how long should my running training be)?

Good afternoon.

1. How to train to run faster? For instance, I run 5 km in 23 minutes but want in 17-18 minutes; I run 3 km in 12.50 but want in 10-11 minutes.
2. How to train for a half marathon and marathon?

Oleg Sergeevich, good afternoon.

I run half-marathons regularly, my personal record is 1:52:00.

I've finished running season and plan to return to running trainings in spring (in late March or in the beginning of April). I have several questions:

1. What date should I choose for my first marathon's start considering that I plan to return to running trainings in March and let's assume that I'll start to train for a marathon since 1st April? I would like to prepare good, it doesn't mean quickly because my main goal is to run a marathon without injuries.
2. Could you give me some recommendations on training plan: frequency of trainings per week, weekly running volume? How will the weekly running mileage change every month?
3. What's number of speed trainings a week? How many long runs should I do?

Thank you.

Good afternoon.

I'm an amateur runner, not a professional but I'd like to run a half-marathon in spring. Please, tell me how many times a week I should train for?

Good afternoon,

My height is about 2 meters. I know about recommendations on power trainings for tall people. Are there recommendations for such people if we say about long-distance running (half-marathon, marathon)?