So you have about 13 weeks until your marathon, is that correct?
Do you have a goal pace in mind?
Training bullet points:
--Continue to gradually increase your weekly mileage and you have nothing to worry about. General rule is no more than 10% increase in weekly mileage per week.
--How many days a week do you run? Day to day consistency can be just as important as total mileage but both are important and usually go hand in hand.
--As you get up in mileage make sure to take care of your body. Stretch more, roll more, make sure you are keeping track of the mileage you've put on your shoes. Get new shoes BEFORE your old shoes start to die and slowly start to incorporate them to your weekly runs.
--Don't worry about where you end up in training. If you only end up getting to a 14 mile long run before you marathon, no big deal. Just slow your pace so you have more room for error.
--Practice taking in a few different kinds of nutrition on training runs. Try GU's since those are usually supplied by races. See if any upset your stomach. This doesn't have to be during a long run but probably would be helpful.
Some bullet points for the race:
--Your biggest issue is going to be pacing. Definitely the hardest thing for runners to gauge when running a marathon. Especially runners that do not have a lot of mileage on their legs. You want to run the race so that you can easily chat with the person next to you without much hesitation.
--The race doesn't start until mile 20. Do not increase your pace until you've hit mile 20.
--Take in nutrition before you need it. I usually do nutrition at mile 6, 12, 18, and whenever needed after 20. Drink water with the nutrition in take in. If I'm taking nutrition in at an aid station I take it with water. If no nutrition at the water stop I go with the sports drink that is being served.
--Make sure you are drinking something at every aid station (usually just one, maybe 2 cups)
--Race your own race. There will be people passing you and you will be passing people at every step of the race. Everyone has different goals so don't worry what others are doing.
--The sleep you get the night before your race isn't as important as the nights leading up to the race. No one sleeps well the night before a race.
--Try to get a few runs in at your expected race time (practice breakfast nutrition, etc. to make sure you what works best for you)
--Set a plan up for parking, bathrooms, etc before the race. Minimize race morning stress by having everything planned.
--Expect the above plan not to go as planned :) And don't worry about it!
--Enjoy the race!! Thank the volunteers at aid stations, the police officers guarding the road crossings, the people cheering you on!