So I'm relatively new to this, and have been running about a year and a half now. I've been training for the last few months for a half marathon tomorrow, but once that's finished, I've decided to commit myself to taking my running a bit more seriously and really achieving my goals.

For context, my goals are to run a sub 20 minute 5k (hopefully this year) and longer term have the capability to really train and race my first marathon. My first 5k last year was 30 minutes, and my last race at christmas was 21:45 so I've been getting there slowly.

I'd initially started hitting the speedwork, but now realise I probably did not have the running experience and strength to really benefit from it. On reading the FAQ here, it seems a period of dedicated basebuilding is the best way to get things started, for both my 5k goal, and building endurance for a future marathon. I've put together this basic plan from the info here: https://docs.google.com/spreadsheet/ccc?key=0AifkHgtDio-YdFZ5NzRoSUJtNzdrQ2VFZ0ZsNHZJT2c#gid=0

I had three questions that I was hoping someone could help me with:

• For my half-marathon, I've been running about 21 mpw for the last 4 weeks. Is the mileage build-up in my programme too slow? Or is it better to be cautious and not overdo it?

• seydar's resources here have been super helpful. But here http://www.reddit.com/r/running/comments/kzi28/moronic_question_monday_your_weekly_stupid/c2ojhjb, he talks about doing strides 2-3x per week. Does he mean do 10x100m at 90% effort three times a week? Should I be focusing on speedwork at all in this programme?

• Is there some level of mileage that's 'minimum' or desirable for my goal of a sub-20 minute 5k? Will 40 mpw need to be a stepping stone onto higher mileage, or will it then be time to focus on speedwork?

Many thanks for any help! The information and advice here has been an absolute inspiration.