Great - not many can do it without any training like you did. But, definitely not the ideal training plan for others
Never did any marathons before. But I did do the Walk For Hunger and walked all 20 miles. Other than that I'm trying to exercise and workout more.
I allmost participate Prague Marathon this year (going to be next month) After doing the semi-marathon on December. You are defenetly can do it, You don't even need to train every day, 4 days a week will be fine (I had 3), I built to myself a training program even a child can understand and follow, if you want PM me and I'll explain it to you. Good for you for your decision, ALL THE BEST
Start slow. The most important thing is not to injure yourself. If you are already running 8k, then that is a very good start. Build up your mileage every week, slowly but surely. My personal pattern is to run 2-3 moderate runs during the week (8-16 Km) and then a long run during the weekend. Remember, you don't have to have run 26 miles in training to do a real marathon. Once your long run gets up to about 20 miles you will be able to make it the whole way. Also, a training partner of similar ability is very helpful. Oh, and don't underestimate the importance of the proper shoes. Go to a running store so they can measure your gait and pronation. Trust me, you don't want to have blisters or swollen feet during the race. Also expirament with differnt kinds of socks. It seems silly but it is important. If your feet can survive, and you've done 20 miles a couple of times, you will be able to do 26 miles.